fix: background heal to call HealFormat only if needed (#9491)

In large setups this avoids unnecessary data transfer
across nodes and potential locks.

This PR also optimizes heal result channel, which should
be avoided for each queueHealTask as its expensive
to create/close channels for large number of objects.

cmd/background-heal-ops.go

@@ -18,7 +18,6 @@ package cmd
 
 import (
 	"context"
-	"path"
 	"time"
 
 	"github.com/minio/minio/cmd/logger"
@@ -89,10 +88,10 @@ func (h *healRoutine) run(ctx context.Context, objAPI ObjectLayer) {
 			case bucket != "" && object != "":
 				res, err = objAPI.HealObject(ctx, bucket, object, task.opts)
 			}
-			ObjectPathUpdated(path.Join(bucket, object))
-			if task.responseCh != nil {
-				task.responseCh <- healResult{result: res, err: err}
+			if task.path != slashSeparator && task.path != nopHeal {
+				ObjectPathUpdated(task.path)
 			}
+			task.responseCh <- healResult{result: res, err: err}
 		case <-h.doneCh:
 			return
 		case <-ctx.Done():