wifi: rtw89: use readable return 0 in rtw89_mac_cfg_ppdu_status()

For normal (successful) flow, it must return 0. The original code uses
'return ret', and then we need to backward reference to initial value to
know 'ret = 0'. Changing them to 'return 0', because it will be more
readable and intuitive. This patch doesn't change logic at all.
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <error27@gmail.com>
Link: https://lore.kernel.org/r/202302101023.ctlih5q0-lkp@intel.com/Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20230213091328.25481-1-pkshih@realtek.com

drivers/net/wireless/realtek/rtw89/mac.c

@@ -4554,7 +4554,7 @@ EXPORT_SYMBOL(rtw89_mac_get_txpwr_cr);
 int rtw89_mac_cfg_ppdu_status(struct rtw89_dev *rtwdev, u8 mac_idx, bool enable)
 {
 	u32 reg = rtw89_mac_reg_by_idx(R_AX_PPDU_STAT, mac_idx);
-	int ret = 0;
+	int ret;
 
 	ret = rtw89_mac_check_mac_en(rtwdev, mac_idx, RTW89_CMAC_SEL);
 	if (ret)
@@ -4562,7 +4562,7 @@ int rtw89_mac_cfg_ppdu_status(struct rtw89_dev *rtwdev, u8 mac_idx, bool enable)
 
 	if (!enable) {
 		rtw89_write32_clr(rtwdev, reg, B_AX_PPDU_STAT_RPT_EN);
-		return ret;
+		return 0;
 	}
 
 	rtw89_write32(rtwdev, reg, B_AX_PPDU_STAT_RPT_EN |
@@ -4572,7 +4572,7 @@ int rtw89_mac_cfg_ppdu_status(struct rtw89_dev *rtwdev, u8 mac_idx, bool enable)
 	rtw89_write32_mask(rtwdev, R_AX_HW_RPT_FWD, B_AX_FWD_PPDU_STAT_MASK,
 			   RTW89_PRPT_DEST_HOST);
 
-	return ret;
+	return 0;
 }
 EXPORT_SYMBOL(rtw89_mac_cfg_ppdu_status);