[PATCH] Char: isicom, fix locking in isr

2 spin_unlocks are omitted in the interrupt handler.  Put them there to fix up
deadlocking on UP.

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>