return correct context errors for locking operations (#14569)
return correct context errors for locking operations (#14569)

if a context is canceled do not need to return a timeout error
instead, return the appropriate error for context canceled.
balamurugana/minio,minio/minio,minio/minio,vadmeste/minio,krisis/minio,donatello/minio,balamurugana/minio,donatello/minio,vadmeste/minio,krisis/minio