qemu: domain: Remove code assuming disk format probing

After commit c95f50cb we always set a disk format in the
post parse callback so the code that mandates use of explicit format for
shareable disks no longer makes sense.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

src/qemu/qemu_domain.c

@@ -4642,21 +4642,13 @@ qemuDomainDeviceDefValidateDisk(const virDomainDiskDef *disk,
     const char *driverName = virDomainDiskGetDriver(disk);
     virStorageSourcePtr n;
 
-    if (disk->src->shared && !disk->src->readonly) {
-        if (disk->src->format <= VIR_STORAGE_FILE_AUTO) {
-            virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
-                           _("shared access for disk '%s' requires use of "
-                             "explicitly specified disk format"), disk->dst);
-            return -1;
-        }
-
-        if (!qemuBlockStorageSourceSupportsConcurrentAccess(disk->src)) {
+    if (disk->src->shared && !disk->src->readonly &&
+        !qemuBlockStorageSourceSupportsConcurrentAccess(disk->src)) {
         virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
                        _("shared access for disk '%s' requires use of "
                          "supported storage format"), disk->dst);
         return -1;
     }
-    }
 
     if (disk->geometry.cylinders > 0 &&
         disk->geometry.heads > 0 &&