[PATCH] bcm43xx: Fix assertion failures in interrupt handler

In the bcm43xx interrupt handler, sanity checks are wrongly done before the
verification that the interrupt is for the bcm43xx.

Signed-off-by: Pavel Roskin <proski@gnu.org>
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>