staging: rtl8723bs: Use min() instead of doing it manually

Fix following coccicheck warning:
drivers/staging/rtl8723bs/core/rtw_xmit.c:452:25-26: WARNING opportunity for min()

Signed-off-by: Haowen Bai <baihaowen@meizu.com>
Link: https://lore.kernel.org/r/1646983052-16390-1-git-send-email-baihaowen@meizu.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: Lotte-Bai

drivers/staging/rtl8723bs/core/rtw_xmit.c

@@ -449,10 +449,7 @@ static void update_attrib_phy_info(struct adapter *padapter, struct pkt_attrib *
 
 	pattrib->raid = psta->raid;
 
-	if (mlmeext->cur_bwmode < psta->bw_mode)
-		pattrib->bwmode = mlmeext->cur_bwmode;
-	else
-		pattrib->bwmode = psta->bw_mode;
+	pattrib->bwmode = min(mlmeext->cur_bwmode, psta->bw_mode);
 
 	pattrib->sgi = query_ra_short_GI(psta);