[PATCH] ipw2200: Missing kmalloc check

The ipw2200 driver code in current GIT contains a kmalloc() followed by
a memset() without handling a possible memory allocation failure.

Signed-off-by: Panagiotis Issaris <panagiotis.issaris@gmail.com>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>