ocfs2: punch hole should return EINVAL if the length argument in ioctl is negative

An unreserve space ioctl OCFS2_IOC_UNRESVSP/64 should reject a negative
length.

Orabug:14789508

Signed-off-by: Tariq Saseed <tariq.x.saeed@oracle.com>
Signed-off-by: Srinivas Eeda <srinivas.eeda@oracle.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>