qemu_snapshot: fix memory leak when reverting external snapshot

The code cleaning up virStorageSource doesn't free data allocated by
virStorageSourceInit() so we need to call virStorageSourceDeinit()
explicitly.

Fixes: 8e66473781
Resolves: https://issues.redhat.com/browse/RHEL-33044
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Jiri Denemark <jdenemar@redhat.com>

src/qemu/qemu_snapshot.c

@@ -2260,6 +2260,8 @@ qemuSnapshotRevertExternalFinish(virDomainObj *vm,
                          snapdisk->src->path);
             }
 
+            virStorageSourceDeinit(snapdisk->src);
+
             virDomainSnapshotDiskDefClear(snapdisk);
         }
 
@@ -2277,6 +2279,8 @@ qemuSnapshotRevertExternalFinish(virDomainObj *vm,
                 VIR_WARN("Failed to remove snapshot image '%s'",
                          snapdisk->src->path);
             }
+
+            virStorageSourceDeinit(snapdisk->src);
         }
     }