staging: wlags49_h2: fix extern inline functions

Patch not upstream as this driver is deleted there.

Fix up some "extern inline" functions as they break the build when using
a "modern" complier (i.e. gcc5).
Signed-off-by: Jiri Slaby <jslaby@suse.cz>

drivers/staging/wlags49_h2/wl_internal.h

@@ -1013,7 +1013,7 @@ static inline void wl_unlock(struct wl_private *lp,
 /* Interrupt enable disable functions                               */
 /********************************************************************/
 
-extern inline void wl_act_int_on(struct wl_private *lp)
+static inline void wl_act_int_on(struct wl_private *lp)
 {
 	/*
 	 * Only do something when the driver is handling
@@ -1025,7 +1025,7 @@ extern inline void wl_act_int_on(struct wl_private *lp)
 	}
 }
 
-extern inline void wl_act_int_off(struct wl_private *lp)
+static inline void wl_act_int_off(struct wl_private *lp)
 {
 	/*
 	 * Only do something when the driver is handling