Merge pull request #3946 from dgquintas/wut

Fixed an inexplicable wrong handling of a lock
diff --git a/src/core/channel/client_uchannel.c b/src/core/channel/client_uchannel.c
index fee0c54..510677a 100644
--- a/src/core/channel/client_uchannel.c
+++ b/src/core/channel/client_uchannel.c
@@ -462,7 +462,7 @@
   grpc_subchannel_state_change_unsubscribe(exec_ctx, chand->subchannel,
                                            &chand->connectivity_cb);
   grpc_connectivity_state_destroy(exec_ctx, &chand->state_tracker);
-  gpr_mu_lock(&chand->mu_state);
+  gpr_mu_destroy(&chand->mu_state);
 }
 
 const grpc_channel_filter grpc_client_uchannel_filter = {