staging: rtl8723bs: core: Remove unnecessary parentheses

Removes unnecessary parentheses while returning an expression.Issue
found using coccinelle.
Semantic patch used to solve the problem is as follows:

@@
expression e;
@@

return
-(
e
-)
;
Signed-off-by: Vatsala Narang <vatsalanarang@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rtl8723bs/core/rtw_wlan_util.c

@@ -518,7 +518,7 @@ unsigned int decide_wait_for_beacon_timeout(unsigned int bcn_interval)
 	else if ((bcn_interval << 2) > WAIT_FOR_BCN_TO_MAX)
 		return WAIT_FOR_BCN_TO_MAX;
 	else
-		return ((bcn_interval << 2));
+		return bcn_interval << 2;
 }
 
 void invalidate_cam_all(struct adapter *padapter)