staging: wilc1000: Avoid GFP_KERNEL allocation from atomic context.

Since wilc_set_multicast_list() is called with dev->addr_list_lock
spinlock held, we can't use GFP_KERNEL memory allocation.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Fixes: e624c58c ("staging: wilc1000: refactor code to avoid use of wilc_set_multicast_list global")
Cc: Ajay Singh <ajay.kathat@microchip.com>
Reviewed-by: Adham Abozaeid <adham.abozaeid@microchip.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>