Deprecate ListLocks and ClearLocks (#6233)

No locks are ever left in memory, we also
have a periodic interval of clearing stale locks
anyways. The lock instrumentation was not complete
and was seldom used.

Deprecate this for now and bring it back later if
it is really needed. This also in-turn seems to improve
performance slightly.

cmd/fs-v1.go

@@ -265,18 +265,6 @@ func (fs *FSObjects) StorageInfo(ctx context.Context) StorageInfo {
 	return storageInfo
 }
 
-// Locking operations
-
-// ListLocks - List namespace locks held in object layer
-func (fs *FSObjects) ListLocks(ctx context.Context, bucket, prefix string, duration time.Duration) ([]VolumeLockInfo, error) {
-	return []VolumeLockInfo{}, NotImplemented{}
-}
-
-// ClearLocks - Clear namespace locks held in object layer
-func (fs *FSObjects) ClearLocks(ctx context.Context, info []VolumeLockInfo) error {
-	return NotImplemented{}
-}
-
 /// Bucket operations
 
 // getBucketDir - will convert incoming bucket names to