qemu: Clean up qemuDomainSecretPrepare

No need to pass a @driver parameter since all that's done is deref
the @cfg especially since the only caller can just pass an already
referenced @cfg.

Also, looks like commit id '0298531b' at one time had a different
name for the API, so I took the liberty of fixing the comments too
since I would already be updating them for the @cfg variable.

src/qemu/qemu_domain.c

@@ -7494,7 +7494,7 @@ qemuDomainPrepareChannel(virDomainChrDefPtr channel,
 }
 
 
-/* qemuProcessPrepareDomainChardevSourceTLS:
+/* qemuDomainPrepareChardevSourceTLS:
  * @source: pointer to host interface data for char devices
  * @cfg: driver configuration
  *
@@ -7518,19 +7518,18 @@ qemuDomainPrepareChardevSourceTLS(virDomainChrSourceDefPtr source,
 }
 
 
-/* qemuProcessPrepareDomainChardevSource:
+/* qemuDomainPrepareChardevSource:
  * @def: live domain definition
- * @driver: qemu driver
+ * @cfg: driver configuration
  *
  * Iterate through all devices that use virDomainChrSourceDefPtr as host
  * interface part.
  */
 void
 qemuDomainPrepareChardevSource(virDomainDefPtr def,
-                               virQEMUDriverPtr driver)
+                               virQEMUDriverConfigPtr cfg)
 {
     size_t i;
-    virQEMUDriverConfigPtr cfg = virQEMUDriverGetConfig(driver);
 
     for (i = 0; i < def->nserials; i++)
         qemuDomainPrepareChardevSourceTLS(def->serials[i]->source, cfg);
@@ -7555,8 +7554,6 @@ qemuDomainPrepareChardevSource(virDomainDefPtr def,
 
     for (i = 0; i < def->nredirdevs; i++)
         qemuDomainPrepareChardevSourceTLS(def->redirdevs[i]->source, cfg);
-
-    virObjectUnref(cfg);
 }
 
 

src/qemu/qemu_domain.h

@@ -861,7 +861,7 @@ void qemuDomainPrepareChardevSourceTLS(virDomainChrSourceDefPtr source,
     ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2);
 
 void qemuDomainPrepareChardevSource(virDomainDefPtr def,
-                                    virQEMUDriverPtr driver)
+                                    virQEMUDriverConfigPtr cfg)
     ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2);
 
 int qemuDomainPrepareShmemChardev(virDomainShmemDefPtr shmem)

src/qemu/qemu_process.c

@@ -5323,7 +5323,7 @@ qemuProcessPrepareDomain(virConnectPtr conn,
         goto cleanup;
 
     VIR_DEBUG("Prepare chardev source backends for TLS");
-    qemuDomainPrepareChardevSource(vm->def, driver);
+    qemuDomainPrepareChardevSource(vm->def, cfg);
 
     VIR_DEBUG("Add secrets to disks, hostdevs, and chardevs");
     if (qemuDomainSecretPrepare(conn, driver, vm) < 0)