re-use the same local drive used by remote-peer (#18645)

historically, we have always kept storage-rest-server
and a local storage API separate without much trouble,
since they both can independently operate due to no
special state() between them.

however, over some time, we have added state()
such as

- drive monitoring threads now there will be "2" of
  them per drive instead of just 1.

- concurrent tokens available per drive are now twice
  instead of just single shared, allowing unexpectedly
  high amount of I/O to go through.

- applying serialization by using walkMutexes can now
  be adequately honored for both remote callers and local
  callers.

cmd/background-newdisks-heal-ops.go

@@ -345,18 +345,18 @@ func initAutoHeal(ctx context.Context, objAPI ObjectLayer) {
 
 	initBackgroundHealing(ctx, objAPI) // start quick background healing
 
-	globalBackgroundHealState.pushHealLocalDisks(getLocalDisksToHeal()...)
-
 	if env.Get("_MINIO_AUTO_DRIVE_HEALING", config.EnableOn) == config.EnableOn || env.Get("_MINIO_AUTO_DISK_HEALING", config.EnableOn) == config.EnableOn {
+		globalBackgroundHealState.pushHealLocalDisks(getLocalDisksToHeal()...)
+
 		go monitorLocalDisksAndHeal(ctx, z)
 	}
 }
 
 func getLocalDisksToHeal() (disksToHeal Endpoints) {
 	globalLocalDrivesMu.RLock()
-	globalLocalDrives := globalLocalDrives
+	localDrives := globalLocalDrives
 	globalLocalDrivesMu.RUnlock()
-	for _, disk := range globalLocalDrives {
+	for _, disk := range localDrives {
 		_, err := disk.GetDiskID()
 		if errors.Is(err, errUnformattedDisk) {
 			disksToHeal = append(disksToHeal, disk.Endpoint())