Fix wrong reporting of total disks after restart (#13326)

A restart of the cluster and a failed disk will wrongly count 
the number of total disks.

cmd/erasure-common.go

@@ -22,16 +22,6 @@ import (
 	"sync"
 )
 
-func (er erasureObjects) getLocalDisks() (localDisks []StorageAPI) {
-	disks := er.getDisks()
-	for _, disk := range disks {
-		if disk != nil && disk.IsLocal() {
-			localDisks = append(localDisks, disk)
-		}
-	}
-	return localDisks
-}
-
 func (er erasureObjects) getLoadBalancedLocalDisks() (newDisks []StorageAPI) {
 	disks := er.getDisks()
 	// Based on the random shuffling return back randomized disks.