tolerate listing with only readQuorum disks (#10357)

We can reduce this further in the future, but this is a good
value to keep around. With the advent of continuous healing,
we can be assured that namespace will eventually be
consistent so we are okay to avoid the necessity to
a list across all drives on all sets.

Bonus Pop()'s in parallel seem to have the potential to
wait too on large drive setups and cause more slowness
instead of gaining any performance remove it for now.

Also, implement load balanced reply for local disks,
ensuring that local disks have an affinity for

- cleanupStaleMultipartUploads()

cmd/xl-storage.go

@@ -842,11 +842,7 @@ func (s *xlStorage) WalkSplunk(volume, dirPath, marker string, endWalkCh <-chan
 		}
 
 		walkResultCh := startTreeWalk(GlobalContext, volume, dirPath, marker, true, listDir, s.isLeafSplunk, s.isLeafDir, endWalkCh)
-		for {
-			walkResult, ok := <-walkResultCh
-			if !ok {
-				return
-			}
+		for walkResult := range walkResultCh {
 			var fi FileInfo
 			if HasSuffix(walkResult.entry, SlashSeparator) {
 				fi = FileInfo{