staging: line6: pcm.c fix checkpatch issues

fix those checkpatch issues
drivers/staging/line6/pcm.c:84:
	WARNING: simple_strtoul is obsolete, use kstrtoul instead
	call to obsolete simple_strtoul() replaced by kstrtoint()

drivers/staging/line6/pcm.c:423:
	ERROR: switch and case should be at the same indent
	realigns comments
Signed-off-by: Laurent Navet <laurent.navet@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/line6/pcm.c

@@ -49,11 +49,11 @@ static ssize_t pcm_set_impulse_volume(struct device *dev,
 {
 	struct snd_line6_pcm *line6pcm = dev2pcm(dev);
 	int value;
-	int rv;
+	int ret;
 
-	rv = kstrtoint(buf, 10, &value);
-	if (rv < 0)
-		return rv;
+	ret = kstrtoint(buf, 10, &value);
+	if (ret < 0)
+		return ret;
 
 	line6pcm->impulse_volume = value;
 
@@ -81,7 +81,14 @@ static ssize_t pcm_set_impulse_period(struct device *dev,
 				      struct device_attribute *attr,
 				      const char *buf, size_t count)
 {
-	dev2pcm(dev)->impulse_period = simple_strtoul(buf, NULL, 10);
+	int value;
+	int ret;
+
+	ret = kstrtoint(buf, 10, &value);
+	if (ret < 0)
+		return ret;
+
+	dev2pcm(dev)->impulse_period = value;
 	return count;
 }
 
@@ -460,8 +467,7 @@ int line6_init_pcm(struct usb_line6 *line6,
 	case LINE6_DEVID_PODSTUDIO_UX2:
 		ep_read  = 0x87;
 		ep_write = 0x00;
-		   break;
-		 */
+		break; */
 
 	default:
 		MISSING_CASE;