Trivial cleanups for nbd: only the return -EIO one really changes code,
and I've verified all the callers (plus 0 == success, 1 == error
convention is really ugly).
Signed-off-by: NPavel Machek <pavel@suse.cz>
Acked-by: NPaul Clements <paul.clements@steeleye.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>