staging: wilc1000: fix return error code of wilc_deinit

It should be returned error code as -EFAULT instead of 0 when hif_drv is
NULL.

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