cciss: unlock on error path

We take the spin_lock again in fail_all_cmds() so we need to unlock here.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Acked-by: Steve Cameron <scameron@beardog.cce.hp.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>