[PATCH] zd1211rw: Fix of a locking bug

This patch fixes the bug as reported in the kernel bug tracker
under the id 7244. The bug was simply that the interrupt lock has
been locked outside an interrupt without blocking the interrupt.

Signed-off-by: Ulrich Kunitz <kune@deine-taler.de>
Signed-off-by: Daniel Drake <dsd@gentoo.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>