qemuDomainDeviceDefPostParse: Drop useless checks

Now that virQEMUDriverCreateXMLConf is never called with NULL
(after 086f37e9) we can safely drop useless check in
qemuDomainDeviceDefPostParse as we are guaranteed to be always
called with the driver initialized. Therefore checking if driver
is NULL makes no sense. Moreover, if we mix it with direct driver
dereference. And after that, we are sure that nor @cfg will be
NULL, therefore we can drop checks for that too.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

src/qemu/qemu_domain.c

@@ -1233,12 +1233,9 @@ qemuDomainDeviceDefPostParse(virDomainDeviceDefPtr dev,
 {
     virQEMUDriverPtr driver = opaque;
     virQEMUCapsPtr qemuCaps = NULL;
-    virQEMUDriverConfigPtr cfg = NULL;
+    virQEMUDriverConfigPtr cfg = virQEMUDriverGetConfig(driver);
     int ret = -1;
 
-    if (driver)
-        cfg = virQEMUDriverGetConfig(driver);
-
     qemuCaps = virQEMUCapsCacheLookup(driver->qemuCapsCache, def->emulator);
 
     if (dev->type == VIR_DOMAIN_DEVICE_NET &&
@@ -1253,37 +1250,34 @@ qemuDomainDeviceDefPostParse(virDomainDeviceDefPtr dev,
     if (dev->type == VIR_DOMAIN_DEVICE_DISK) {
         virDomainDiskDefPtr disk = dev->data.disk;
 
-        /* both of these require data from the driver config */
-        if (cfg) {
-            /* assign default storage format and driver according to config */
-            if (cfg->allowDiskFormatProbing) {
-                /* default disk format for drives */
-                if (virDomainDiskGetFormat(disk) == VIR_STORAGE_FILE_NONE &&
-                    (virDomainDiskGetType(disk) == VIR_STORAGE_TYPE_FILE ||
-                     virDomainDiskGetType(disk) == VIR_STORAGE_TYPE_BLOCK))
-                    virDomainDiskSetFormat(disk, VIR_STORAGE_FILE_AUTO);
-
-                /* default disk format for mirrored drive */
-                if (disk->mirror &&
-                    disk->mirror->format == VIR_STORAGE_FILE_NONE)
-                    disk->mirror->format = VIR_STORAGE_FILE_AUTO;
-            } else {
-                /* default driver if probing is forbidden */
-                if (!virDomainDiskGetDriver(disk) &&
-                    virDomainDiskSetDriver(disk, "qemu") < 0)
-                    goto cleanup;
-
-                /* default disk format for drives */
-                if (virDomainDiskGetFormat(disk) == VIR_STORAGE_FILE_NONE &&
-                    (virDomainDiskGetType(disk) == VIR_STORAGE_TYPE_FILE ||
-                     virDomainDiskGetType(disk) == VIR_STORAGE_TYPE_BLOCK))
-                    virDomainDiskSetFormat(disk, VIR_STORAGE_FILE_RAW);
-
-                /* default disk format for mirrored drive */
-                if (disk->mirror &&
-                    disk->mirror->format == VIR_STORAGE_FILE_NONE)
-                    disk->mirror->format = VIR_STORAGE_FILE_RAW;
-            }
+        /* assign default storage format and driver according to config */
+        if (cfg->allowDiskFormatProbing) {
+            /* default disk format for drives */
+            if (virDomainDiskGetFormat(disk) == VIR_STORAGE_FILE_NONE &&
+                (virDomainDiskGetType(disk) == VIR_STORAGE_TYPE_FILE ||
+                 virDomainDiskGetType(disk) == VIR_STORAGE_TYPE_BLOCK))
+                virDomainDiskSetFormat(disk, VIR_STORAGE_FILE_AUTO);
+
+            /* default disk format for mirrored drive */
+            if (disk->mirror &&
+                disk->mirror->format == VIR_STORAGE_FILE_NONE)
+                disk->mirror->format = VIR_STORAGE_FILE_AUTO;
+        } else {
+            /* default driver if probing is forbidden */
+            if (!virDomainDiskGetDriver(disk) &&
+                virDomainDiskSetDriver(disk, "qemu") < 0)
+                goto cleanup;
+
+            /* default disk format for drives */
+            if (virDomainDiskGetFormat(disk) == VIR_STORAGE_FILE_NONE &&
+                (virDomainDiskGetType(disk) == VIR_STORAGE_TYPE_FILE ||
+                 virDomainDiskGetType(disk) == VIR_STORAGE_TYPE_BLOCK))
+                virDomainDiskSetFormat(disk, VIR_STORAGE_FILE_RAW);
+
+            /* default disk format for mirrored drive */
+            if (disk->mirror &&
+                disk->mirror->format == VIR_STORAGE_FILE_NONE)
+                disk->mirror->format = VIR_STORAGE_FILE_RAW;
         }
     }
 
@@ -1315,12 +1309,6 @@ qemuDomainDeviceDefPostParse(virDomainDeviceDefPtr dev,
         dev->data.chr->targetType == VIR_DOMAIN_CHR_CHANNEL_TARGET_TYPE_VIRTIO &&
         dev->data.chr->source.type == VIR_DOMAIN_CHR_TYPE_UNIX &&
         !dev->data.chr->source.data.nix.path) {
-        if (!cfg) {
-            virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
-                           _("cannot generate UNIX socket path"));
-            goto cleanup;
-        }
-
         if (virAsprintf(&dev->data.chr->source.data.nix.path,
                         "%s/domain-%s/%s",
                         cfg->channelTargetDir, def->name,