util: Free a pointer in virPolkitCheckAuth

Free DBusMessage pointer in virPolkitCheckAuth
Signed-off-by: NKothapally Madhu Pavan <kmp@linux.vnet.ibm.com>

src/util/virpolkit.c

@@ -138,6 +138,7 @@ int virPolkitCheckAuth(const char *actionid,
 
  cleanup:
     virStringListFreeCount(retdetails, nretdetails);
+    virDBusMessageUnref(reply);
     return ret;
 }