The function check_dev_ioctl_version() returns an error code upon fail but
it isn't captured and returned in validate_dev_ioctl() as it should be.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: NIan Kent <raven@themaw.net>
Signed-off-by: NJeff Moyer <jmoyer@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>