staging: wilc1000: fix return error code

Three argument are checked at the beginning of wilc_mq_send whether
they are valid arguments or not. It is correct to use return error code
as -EINVAL, not -EFAULT.

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