staging: vt6656: iwctl.c: Rewrite siwrts funciton

This function has the following issues:
	Parameter info and extra are not used
	Wrong error handling(the function not return -EINVAL when it
happens)

This patch simplifies this funtion, remove the not used parameters and
fix the error handilng.
Signed-off-by: Marcos Paulo de Souza <marcos.mage@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/vt6656/iwctl.c

@@ -1010,27 +1010,19 @@ void iwctl_giwrate(struct net_device *dev,
 /*
  * Wireless Handler : set rts threshold
  */
-
 int iwctl_siwrts(struct net_device *dev,
-             struct iw_request_info *info,
-			 struct iw_param *wrq,
-             char *extra)
+		 struct iw_param *wrq)
 {
-	PSDevice	        pDevice = (PSDevice)netdev_priv(dev);
-	int rc = 0;
+	PSDevice pDevice = (PSDevice)netdev_priv(dev);
 
-    DBG_PRT(MSG_LEVEL_DEBUG, KERN_INFO " SIOCSIWRTS \n");
+	if ((wrq->value < 0 || wrq->value > 2312) && !wrq->disabled)
+		return -EINVAL;
 
-	{
-	    int rthr = wrq->value;
-	    if(wrq->disabled)
-			rthr = 2312;
-	    if((rthr < 0) || (rthr > 2312)) {
-			rc = -EINVAL;
-    	}else {
-		    pDevice->wRTSThreshold = rthr;
-	    }
-    }
+	else if (wrq->disabled)
+		pDevice->wRTSThreshold = 2312;
+
+	else
+		pDevice->wRTSThreshold = wrq->value;
 
 	return 0;
 }

drivers/staging/vt6656/iwctl.h

@@ -113,10 +113,7 @@ void iwctl_giwrate(struct net_device *dev,
              char *extra);
 
 int iwctl_siwrts(struct net_device *dev,
-             struct iw_request_info *info,
-			 struct iw_param *wrq,
-             char *extra);
-
+		 struct iw_param *wrq);
 
 int iwctl_giwrts(struct net_device *dev,
              struct iw_request_info *info,

drivers/staging/vt6656/main_usb.c

@@ -1704,7 +1704,7 @@ static int  device_ioctl(struct net_device *dev, struct ifreq *rq, int cmd) {
 	// Set the desired RTS threshold
 	case SIOCSIWRTS:
 
-		rc = iwctl_siwrts(dev, NULL, &(wrq->u.rts), NULL);
+		rc = iwctl_siwrts(dev, &(wrq->u.rts));
 		break;
 
 	// Get the current RTS threshold