staging: r8188eu: convert rtw_setdatarate_cmd to correct error semantics

Convert rtw_setdatarate_cmd function to use proper error return codes
rather than _SUCCESS and _FAIL, and a simpler 'return 0;' style. For now,
wrap rtw_enqueue_cmd call and return -EPERM if it fails, as converting
this function makes more sense later on due to its large number of callers.

Also change rtw_wx_set_rate function to pass through the proper error
code rather than just 0 or -1.
Signed-off-by: Phillip Potter <phil@philpotter.co.uk>
Link: https://lore.kernel.org/r/20221102003613.971-1-phil@philpotter.co.ukSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/r8188eu/core/rtw_cmd.c

@@ -340,33 +340,29 @@ u8 rtw_sitesurvey_cmd(struct adapter  *padapter, struct ndis_802_11_ssid *ssid,
 	return res;
 }
 
-u8 rtw_setdatarate_cmd(struct adapter *padapter, u8 *rateset)
+int rtw_setdatarate_cmd(struct adapter *padapter, u8 *rateset)
 {
 	struct cmd_obj *ph2c;
 	struct setdatarate_parm *pbsetdataratepara;
 	struct cmd_priv *pcmdpriv = &padapter->cmdpriv;
-	u8	res = _SUCCESS;
 
 	ph2c = kzalloc(sizeof(*ph2c), GFP_ATOMIC);
-	if (!ph2c) {
-		res = _FAIL;
-		goto exit;
-	}
+	if (!ph2c)
+		return -ENOMEM;
 
 	pbsetdataratepara = kzalloc(sizeof(*pbsetdataratepara), GFP_ATOMIC);
 	if (!pbsetdataratepara) {
 		kfree(ph2c);
-		res = _FAIL;
-		goto exit;
+		return -ENOMEM;
 	}
 
 	init_h2fwcmd_w_parm_no_rsp(ph2c, pbsetdataratepara, GEN_CMD_CODE(_SetDataRate));
 	pbsetdataratepara->mac_id = 5;
 	memcpy(pbsetdataratepara->datarates, rateset, NumRates);
-	res = rtw_enqueue_cmd(pcmdpriv, ph2c);
-exit:
+	if (rtw_enqueue_cmd(pcmdpriv, ph2c) == _FAIL)
+		return -EPERM;
 
-	return res;
+	return 0;
 }
 
 void rtw_getbbrfreg_cmdrsp_callback(struct adapter *padapter,  struct cmd_obj *pcmd)

drivers/staging/r8188eu/include/rtw_cmd.h

@@ -727,7 +727,7 @@ u8 rtw_clearstakey_cmd(struct adapter *padapter, u8 *psta, u8 entry, u8 enqueue)
 u8 rtw_joinbss_cmd(struct adapter *padapter, struct wlan_network *pnetwork);
 u8 rtw_disassoc_cmd(struct adapter *padapter, u32 deauth_timeout_ms, bool enqueue);
 u8 rtw_setopmode_cmd(struct adapter *padapter, enum ndis_802_11_network_infra networktype);
-u8 rtw_setdatarate_cmd(struct adapter *padapter, u8 *rateset);
+int rtw_setdatarate_cmd(struct adapter *padapter, u8 *rateset);
 u8 rtw_setrfintfs_cmd(struct adapter *padapter, u8 mode);
 
 u8 rtw_gettssi_cmd(struct adapter *padapter, u8 offset, u8 *pval);

drivers/staging/r8188eu/os_dep/ioctl_linux.c

@@ -1340,7 +1340,7 @@ static int rtw_wx_set_rate(struct net_device *dev,
 			      struct iw_request_info *a,
 			      union iwreq_data *wrqu, char *extra)
 {
-	int i, ret = 0;
+	int i;
 	struct adapter *padapter = (struct adapter *)rtw_netdev_priv(dev);
 	u8 datarates[NumRates];
 	u32	target_rate = wrqu->bitrate.value;
@@ -1408,10 +1408,7 @@ static int rtw_wx_set_rate(struct net_device *dev,
 		}
 	}
 
-	if (rtw_setdatarate_cmd(padapter, datarates) != _SUCCESS)
-		ret = -1;
-
-	return ret;
+	return rtw_setdatarate_cmd(padapter, datarates);
 }
 
 static int rtw_wx_get_rate(struct net_device *dev,