while compiling integer err was showing as a set but unused variable.
elevator_init_fn can be either cfq_init_queue or deadline_init_queue
or noop_init_queue.
all three of these functions are returning -ENOMEM if they fail to
allocate the queue.
so we should actually be returning the error code rather than
returning 0 always.
Signed-off-by: NSudip Mukherjee <sudip@vectorindia.org>
Signed-off-by: NJens Axboe <axboe@fb.com>