cyclades: fix read buffer overflow

irq is declared with size NR_CARDS (4), but the loop containing this
segment runs up until NR_ISA_ADDRS (16), possibly reading from irq[i] (and
trying to use the result)

Identified by the Parfait static scanner.

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