staging: vt6655: Fixed C99 style comment to C89 style.

Patch created to satisfy checkpatch.pl
Signed-off-by: Lior Pugatch <buzz5800@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/vt6655/rxtx.h

@@ -197,4 +197,4 @@ int vnt_beacon_make(struct vnt_private *, struct ieee80211_vif *);
 int vnt_beacon_enable(struct vnt_private *, struct ieee80211_vif *,
 		      struct ieee80211_bss_conf *);
 
-#endif // __RXTX_H__
+#endif /* __RXTX_H__ */