staging: wilc1000: remove pointer varialbe cfg_wait and cfg_wait_event

This patch removes cfg_wait and cfg_wait_event which are pointer of
g_linux_wlan->cfg_event. No need to have pointer varialbe of it. Just use
g_linux_wlan->cfg_event.

Signed-off-by: Glen Lee <glen.lee@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>