rtlwifi: fix non-kerneldoc comment in usb.c

Fix spurious warning message when building with W=1:

  CC [M]  drivers/net/wireless/realtek/rtlwifi/usb.o
drivers/net/wireless/realtek/rtlwifi/usb.c:243: warning: Cannot understand  * on line 243 - I thought it was a doc line
drivers/net/wireless/realtek/rtlwifi/usb.c:760: warning: Cannot understand  * on line 760 - I thought it was a doc line
drivers/net/wireless/realtek/rtlwifi/usb.c:790: warning: Cannot understand  * on line 790 - I thought it was a doc line

Clean up the comment format.
Signed-off-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/realtek/rtlwifi/usb.c

@@ -239,10 +239,7 @@ static void _rtl_usb_io_handler_release(struct ieee80211_hw *hw)
 	mutex_destroy(&rtlpriv->io.bb_mutex);
 }
 
-/**
- *
- *	Default aggregation handler. Do nothing and just return the oldest skb.
- */
+/*	Default aggregation handler. Do nothing and just return the oldest skb.  */
 static struct sk_buff *_none_usb_tx_aggregate_hdl(struct ieee80211_hw *hw,
 						  struct sk_buff_head *list)
 {
@@ -756,11 +753,6 @@ static int rtl_usb_start(struct ieee80211_hw *hw)
 	return err;
 }
 
-/**
- *
- *
- */
-
 /*=======================  tx =========================================*/
 static void rtl_usb_cleanup(struct ieee80211_hw *hw)
 {
@@ -786,11 +778,7 @@ static void rtl_usb_cleanup(struct ieee80211_hw *hw)
 	usb_kill_anchored_urbs(&rtlusb->tx_submitted);
 }
 
-/**
- *
- * We may add some struct into struct rtl_usb later. Do deinit here.
- *
- */
+/* We may add some struct into struct rtl_usb later. Do deinit here.  */
 static void rtl_usb_deinit(struct ieee80211_hw *hw)
 {
 	rtl_usb_cleanup(hw);