libosmo-mgcp-client: mgcp_client_tx(): return rc on error

Change-Id: Ic2080241ceb9e00109a5222b78c35b7971320c21
diff --git a/src/libosmo-mgcp-client/mgcp_client.c b/src/libosmo-mgcp-client/mgcp_client.c
index ffba074..b1909f0 100644
--- a/src/libosmo-mgcp-client/mgcp_client.c
+++ b/src/libosmo-mgcp-client/mgcp_client.c
@@ -1027,12 +1027,12 @@
 
 mgcp_tx_error:
 	if (!pending)
-		return -1;
+		return rc;
 	/* Dequeue pending response, it's going to be free()d */
 	llist_del(&pending->entry);
 	/* Pass NULL to response cb to indicate an error */
 	mgcp_client_handle_response(mgcp, pending, NULL);
-	return -1;
+	return rc;
 }
 
 /*! Cancel a pending transaction.