[PATCH] rt2x00: Clean disabling of rt73usb_get_tsf

By defining rt73usb_get_tsf to NULL we only
have 1 location that needs to be edited
when rt73usb_get_tsf can be enabled again.
This also reduces the number of #ifdefs in
the code which is also a "good thing"
Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/rt2x00/rt73usb.c

@@ -1910,6 +1910,8 @@ static u64 rt73usb_get_tsf(struct ieee80211_hw *hw)
 
 	return tsf;
 }
+#else
+#define rt73usb_get_tsf	NULL
 #endif
 
 static void rt73usb_reset_tsf(struct ieee80211_hw *hw)
@@ -1970,12 +1972,7 @@ static const struct ieee80211_ops rt73usb_mac80211_ops = {
 	.erp_ie_changed		= rt2x00mac_erp_ie_changed,
 	.conf_tx		= rt2x00mac_conf_tx,
 	.get_tx_stats		= rt2x00mac_get_tx_stats,
-#if 0
-/*
- * See comment at the rt73usb_get_tsf function.
- */
 	.get_tsf		= rt73usb_get_tsf,
-#endif
 	.reset_tsf		= rt73usb_reset_tsf,
 	.beacon_update		= rt73usb_beacon_update,
 };