staging: r8188eu: convert rtw_p2p_enable to correct error code semantics

Convert the rtw_p2p_enable function to use correct error code semantics
rather than _SUCCESS/_FAIL, and also make sure we allow these to be
passed through properly in the one caller where we actually check the
code, rtw_wext_p2p_enable.

This change moves these functions to a clearer 'return 0;' style at the
end of the function, and in the case of errors now returns ret instead
of jumping to the end of the function, so that these can still be passed
through but without using a goto to jump to a single return statement at
the end which is less clear.

This change moves the driver slowly closer to using standard error code
semantics everywhere.

Tested-by: Philipp Hortmann <philipp.g.hortmann@gmail.com> # Edimax N150
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Phillip Potter <phil@philpotter.co.uk>
Link: https://lore.kernel.org/r/20220802234408.930-1-phil@philpotter.co.ukSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/r8188eu/core/rtw_p2p.c

@@ -1883,15 +1883,14 @@ void init_wifidirect_info(struct adapter *padapter, enum P2P_ROLE role)
 
 int rtw_p2p_enable(struct adapter *padapter, enum P2P_ROLE role)
 {
-	int ret = _SUCCESS;
+	int ret;
 	struct wifidirect_info *pwdinfo = &padapter->wdinfo;
 
 	if (role == P2P_ROLE_DEVICE || role == P2P_ROLE_CLIENT || role == P2P_ROLE_GO) {
 		/* leave IPS/Autosuspend */
-		if (rtw_pwr_wakeup(padapter)) {
-			ret = _FAIL;
-			goto exit;
-		}
+		ret = rtw_pwr_wakeup(padapter);
+		if (ret)
+			return ret;
 
 		/*	Added by Albert 2011/03/22 */
 		/*	In the P2P mode, the driver should not support the b mode. */
@@ -1902,10 +1901,9 @@ int rtw_p2p_enable(struct adapter *padapter, enum P2P_ROLE role)
 		init_wifidirect_info(padapter, role);
 
 	} else if (role == P2P_ROLE_DISABLE) {
-		if (rtw_pwr_wakeup(padapter)) {
-			ret = _FAIL;
-			goto exit;
-		}
+		ret = rtw_pwr_wakeup(padapter);
+		if (ret)
+			return ret;
 
 		/* Disable P2P function */
 		if (!rtw_p2p_chk_state(pwdinfo, P2P_STATE_NONE)) {
@@ -1923,6 +1921,5 @@ int rtw_p2p_enable(struct adapter *padapter, enum P2P_ROLE role)
 		update_tx_basic_rate(padapter, padapter->registrypriv.wireless_mode);
 	}
 
-exit:
-	return ret;
+	return 0;
 }

drivers/staging/r8188eu/os_dep/ioctl_linux.c

@@ -2079,7 +2079,7 @@ static int rtw_wext_p2p_enable(struct net_device *dev,
 			       struct iw_request_info *info,
 			       union iwreq_data *wrqu, char *extra)
 {
-	int ret = 0;
+	int ret;
 	struct adapter *padapter = (struct adapter *)rtw_netdev_priv(dev);
 	struct wifidirect_info *pwdinfo = &padapter->wdinfo;
 	struct mlme_ext_priv	*pmlmeext = &padapter->mlmeextpriv;
@@ -2094,10 +2094,9 @@ static int rtw_wext_p2p_enable(struct net_device *dev,
 	else if (*extra == '3')
 		init_role = P2P_ROLE_GO;
 
-	if (_FAIL == rtw_p2p_enable(padapter, init_role)) {
-		ret = -EFAULT;
-		goto exit;
-	}
+	ret = rtw_p2p_enable(padapter, init_role);
+	if (ret)
+		return ret;
 
 	/* set channel/bandwidth */
 	if (init_role != P2P_ROLE_DISABLE) {
@@ -2121,8 +2120,7 @@ static int rtw_wext_p2p_enable(struct net_device *dev,
 		set_channel_bwmode(padapter, channel, ch_offset, bwmode);
 	}
 
-exit:
-	return ret;
+	return 0;
 }
 
 static void rtw_p2p_set_go_nego_ssid(struct net_device *dev,