Staging: wlags49_h2: remove unused function prototype

With today linux-next I got a compile error in staging/wlags49_h2 driver
due an unused function prototype that use a data type (event_callback_args_t)
that doesn't exist anymore in the pcmcia code.

Current patch solves the issue removing the function prototype.
Signed-off-by: Javier Martinez Canillas <martinez.javier@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/wlags49_h2/wl_cs.h

@@ -72,8 +72,6 @@ void wl_adapter_insert(struct pcmcia_device *link);
 
 void wl_adapter_release(struct pcmcia_device *link);
 
-int wl_adapter_event(event_t event, int priority, event_callback_args_t *args );
-
 int wl_adapter_init_module( void );
 
 void wl_adapter_cleanup_module( void );