ALSA: line6: Remove superfluous NULL checks in each driver

The interface and driver objects are always set when callbacks are
called.  Drop such superfluous NULL checks in init and disconnect
calls of each driver.

Tested-by: Chris Rorvick <chris@rorvick.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/usb/line6/pod.c b/sound/usb/line6/pod.c
index bf027fc..26ecf26 100644
--- a/sound/usb/line6/pod.c
+++ b/sound/usb/line6/pod.c
@@ -401,25 +401,16 @@
 */
 static void line6_pod_disconnect(struct usb_interface *interface)
 {
-	struct usb_line6_pod *pod;
+	struct usb_line6_pod *pod = usb_get_intfdata(interface);
+	struct device *dev = &interface->dev;
 
-	if (interface == NULL)
-		return;
-	pod = usb_get_intfdata(interface);
+	/* remove sysfs entries: */
+	device_remove_file(dev, &dev_attr_device_id);
+	device_remove_file(dev, &dev_attr_firmware_version);
+	device_remove_file(dev, &dev_attr_serial_number);
 
-	if (pod != NULL) {
-		struct device *dev = &interface->dev;
-
-		if (dev != NULL) {
-			/* remove sysfs entries: */
-			device_remove_file(dev, &dev_attr_device_id);
-			device_remove_file(dev, &dev_attr_firmware_version);
-			device_remove_file(dev, &dev_attr_serial_number);
-		}
-
-		del_timer_sync(&pod->startup_timer);
-		cancel_work_sync(&pod->startup_work);
-	}
+	del_timer_sync(&pod->startup_timer);
+	cancel_work_sync(&pod->startup_work);
 }
 
 /*
@@ -456,9 +447,6 @@
 	init_timer(&pod->startup_timer);
 	INIT_WORK(&pod->startup_work, pod_startup4);
 
-	if ((interface == NULL) || (pod == NULL))
-		return -ENODEV;
-
 	/* create sysfs entries: */
 	err = pod_create_files2(&interface->dev);
 	if (err < 0)
diff --git a/sound/usb/line6/podhd.c b/sound/usb/line6/podhd.c
index 7217fa7..59abbd9 100644
--- a/sound/usb/line6/podhd.c
+++ b/sound/usb/line6/podhd.c
@@ -90,12 +90,8 @@
 static int podhd_init(struct usb_interface *interface,
 		      struct usb_line6 *line6)
 {
-	struct usb_line6_podhd *podhd = (struct usb_line6_podhd *) line6;
 	int err;
 
-	if ((interface == NULL) || (podhd == NULL))
-		return -ENODEV;
-
 	/* initialize MIDI subsystem: */
 	err = line6_init_midi(line6);
 	if (err < 0)
diff --git a/sound/usb/line6/toneport.c b/sound/usb/line6/toneport.c
index c1f61cd..e5669bd 100644
--- a/sound/usb/line6/toneport.c
+++ b/sound/usb/line6/toneport.c
@@ -370,9 +370,6 @@
 	struct usb_line6_toneport *toneport;
 	u16 idProduct;
 
-	if (interface == NULL)
-		return;
-
 	toneport = usb_get_intfdata(interface);
 	del_timer_sync(&toneport->timer);
 	idProduct = le16_to_cpu(toneport->line6.usbdev->descriptor.idProduct);
@@ -393,9 +390,6 @@
 	int err;
 	struct usb_line6_toneport *toneport =  (struct usb_line6_toneport *) line6;
 
-	if ((interface == NULL) || (toneport == NULL))
-		return -ENODEV;
-
 	line6->disconnect = line6_toneport_disconnect;
 
 	/* initialize PCM subsystem: */
diff --git a/sound/usb/line6/variax.c b/sound/usb/line6/variax.c
index 99a58cb..cd3adef 100644
--- a/sound/usb/line6/variax.c
+++ b/sound/usb/line6/variax.c
@@ -214,12 +214,7 @@
 {
 	struct usb_line6_variax *variax;
 
-	if (!interface)
-		return;
-
 	variax = usb_get_intfdata(interface);
-	if (!variax)
-		return;
 
 	del_timer(&variax->startup_timer1);
 	del_timer(&variax->startup_timer2);
@@ -244,9 +239,6 @@
 	init_timer(&variax->startup_timer2);
 	INIT_WORK(&variax->startup_work, variax_startup6);
 
-	if ((interface == NULL) || (variax == NULL))
-		return -ENODEV;
-
 	/* initialize USB buffers: */
 	variax->buffer_activate = kmemdup(variax_activate,
 					  sizeof(variax_activate), GFP_KERNEL);