qemu: Fix domain object leak in qemuDomainInterfaceAddresses

The API didn't use virDomainObjEndAPI to release the domain object thus
it leaked a reference to it.

src/qemu/qemu_driver.c

@@ -19838,8 +19838,7 @@ qemuDomainInterfaceAddresses(virDomainPtr dom,
     }
 
  cleanup:
-    if (vm)
-        virObjectUnlock(vm);
+    virDomainObjEndAPI(&vm);
     return ret;
 }