staging: ks7010: refactor ks_wlan_set_rx_gain function

This commit refactors ks_wlan_set_rx_gain function to
improve readability:
    - error condition is handling the error to avoid an 'else'
    - ternary operator is used to clean if-else block assignment.
Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/ks7010/ks_wlan_net.c

@@ -2327,16 +2327,11 @@ static int ks_wlan_set_rx_gain(struct net_device *dev,
 	if (priv->sleep_mode == SLP_SLEEP)
 		return -EPERM;
 	/* for SLEEP MODE */
-	if (*uwrq >= 0 && *uwrq <= 0xFF)	/* 0-255 */
-		priv->gain.rx_gain = (uint8_t)*uwrq;
-	else
+	if (*uwrq < 0 || *uwrq > 0xFF)
 		return -EINVAL;
 
-	if (priv->gain.rx_gain < 0xFF)
-		priv->gain.rx_mode = 1;
-	else
-		priv->gain.rx_mode = 0;
-
+	priv->gain.rx_gain = (uint8_t)*uwrq;
+	priv->gain.rx_mode = (priv->gain.rx_gain < 0xFF) ? 1 : 0;
 	hostif_sme_enqueue(priv, SME_SET_GAIN);
 	return 0;
 }