rpc: Remove unnecessary calls

The code is not reachable as of commit id: bb85f229. Removed
virKeepAliveStop() and virObjectUnref() because 'ka' cannot be
anything but NULL at the cleanup label.

src/rpc/virnetserverclient.c

@@ -1356,13 +1356,9 @@ virNetServerClientInitKeepAlive(virNetServerClientPtr client,
     virObjectRef(client);
 
     client->keepalive = ka;
-    ka = NULL;
 
 cleanup:
     virObjectUnlock(client);
-    if (ka)
-        virKeepAliveStop(ka);
-    virObjectUnref(ka);
 
     return ret;
 }