[PATCH] Char: isicom, check card state in isr

Check if the card really interrupted us by reading its IO space and eventualy
return IRQ_NONE.

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>