staging: wilc1000: wilc_msgqueue.c: use kmalloc with GFP_ATOMIC

This patch use kmalloc with GFP_ATOMIC instead of WILC_MALLOC.
It is inside the spin lock region.

Signed-off-by: Chaehyun Lim <chaehyun.lim@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>