V4L/DVB (11078): au0828: properly handle non-existent analog inputs

It is not valid to look for dev->board.input == NULL to detect an undefined
analog configuration section, since it is a member of the struct and not a
pointer (hence it will *always* be non-NULL).  Do the check based on whether
the first input is actually a valid input type instead.

Thanks to Michael Krufky <mkrufky@linuxtv.org> for providing sample hardware
of various configurations to test with.
Signed-off-by: Devin Heitmueller <dheitmueller@linuxtv.org>
Signed-off-by: Michael Krufky <mkrufky@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/au0828/au0828-cards.c

@@ -195,7 +195,7 @@ void au0828_card_setup(struct au0828_dev *dev)
 		break;
 	}
 
-	if (dev->board.input != NULL) {
+	if (AUVI_INPUT(0).type != AU0828_VMUX_UNDEFINED) {
 		/* Load the analog demodulator driver (note this would need to
 		   be abstracted out if we ever need to support a different
 		   demod) */

drivers/media/video/au0828/au0828-core.c

@@ -146,7 +146,7 @@ static void au0828_usb_disconnect(struct usb_interface *interface)
 	/* Digital TV */
 	au0828_dvb_unregister(dev);
 
-	if (dev->board.input != NULL)
+	if (AUVI_INPUT(0).type != AU0828_VMUX_UNDEFINED)
 		au0828_analog_unregister(dev);
 
 	/* I2C */
@@ -205,7 +205,7 @@ static int au0828_usb_probe(struct usb_interface *interface,
 	au0828_card_setup(dev);
 
 	/* Analog TV */
-	if (dev->board.input != NULL)
+	if (AUVI_INPUT(0).type != AU0828_VMUX_UNDEFINED)
 		au0828_analog_register(dev, interface);
 
 	/* Digital TV */

drivers/media/video/au0828/au0828.h

@@ -66,7 +66,8 @@
 #define AU0828_MAX_INPUT        4
 
 enum au0828_itype {
-	AU0828_VMUX_COMPOSITE = 1,
+	AU0828_VMUX_UNDEFINED = 0,
+	AU0828_VMUX_COMPOSITE,
 	AU0828_VMUX_SVIDEO,
 	AU0828_VMUX_CABLE,
 	AU0828_VMUX_TELEVISION,