Merge #156939

156939: gossip: fix gossip.callbacks.pending_duration time metric r=pav-kv a=stevendanna

In 32723e5 I reversed this subtraction somehow.

Release note (bug fix): Fix bug that could result in incorrect gossip.callbacks.pending_duration metric value being recorded.

Co-authored-by: Steven Danna <danna@cockroachlabs.com>

Author: craig[bot]

pkg/gossip/infostore.go

@@ -272,7 +272,7 @@ func (is *infoStore) launchCallbackWorker(ambient log.AmbientContext, cw *callba
 				// metrics accordingly.
 				afterQueue := crtime.NowMono()
 				for _, work := range wq {
-					queueDur := work.schedulingTime.Sub(afterQueue)
+					queueDur := afterQueue.Sub(work.schedulingTime)
 					is.metrics.CallbacksPending.Dec(1)
 					if queueDur >= minCallbackDurationToRecord {
 						is.metrics.CallbacksPendingDuration.RecordValue(queueDur.Nanoseconds())