V4L/DVB (9588): Don't load em28xx audio module for digital-only devices

Rework the logic so that the em28xx-alsa module does not get loaded for devices
that don't support analog audio (such as the em2874)

Signed-off-by: Devin Heitmueller <devin.heitmueller@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/video/em28xx/em28xx-audio.c b/drivers/media/video/em28xx/em28xx-audio.c
index 4a42b29..15c03f0 100644
--- a/drivers/media/video/em28xx/em28xx-audio.c
+++ b/drivers/media/video/em28xx/em28xx-audio.c
@@ -426,9 +426,10 @@
 	static int          devnr;
 	int                 err;
 
-	if (dev->has_audio_class) {
+	if (dev->has_alsa_audio != 1) {
 		/* This device does not support the extension (in this case
-		   the device is expecting the snd-usb-audio module) */
+		   the device is expecting the snd-usb-audio module or
+		   doesn't have analog audio support at all) */
 		return 0;
 	}
 
@@ -480,9 +481,10 @@
 	if (dev == NULL)
 		return 0;
 
-	if (dev->has_audio_class) {
+	if (dev->has_alsa_audio != 1) {
 		/* This device does not support the extension (in this case
-		   the device is expecting the snd-usb-audio module */
+		   the device is expecting the snd-usb-audio module or
+		   doesn't have analog audio support at all) */
 		return 0;
 	}