staging: wilc1000: linux_mon: fix error code of kmalloc

This patch fixes error codes as -ENOMEM instead of using -EFAULT if
kmalloc is failed.

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