bgpd: add missing unlock of path_info

when the path info information is queued on the work queue it
is protected by a lock to avoid the rug being pulled whilst it
resides on the queue add an unlock in the error case where we do
no queue the reference to the workqueue.

Signed-off-by: Pat Ruddy <pat@voltanet.io>

bgpd/bgp_labelpool.c

@@ -461,6 +461,9 @@ void bgp_lp_event_chunk(uint8_t keep, uint32_t first, uint32_t last)
 				zlog_debug("%s: labelid %p: request no longer in effect",
 						__func__, labelid);
 			}
+			/* if this was a BGP_LU request, unlock path info node
+			 */
+			check_bgp_lu_cb_unlock(lcb);
 			goto finishedrequest;
 		}