ALSA: hda - Always check array bounds in alc_get_line_out_pfx

commit 71aa5ebe36a4e936eff281b375a4707b6a8320f2 upstream.

Even when CONFIG_SND_DEBUG is not enabled, we don't want to
return an arbitrary memory location when the channel count is
larger than we expected.

Signed-off-by: David Henningsson <david.henningsson@canonical.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/sound/pci/hda/patch_realtek.c b/sound/pci/hda/patch_realtek.c
index 94747f8..94b765b 100644
--- a/sound/pci/hda/patch_realtek.c
+++ b/sound/pci/hda/patch_realtek.c
@@ -2665,8 +2665,10 @@
 			return "PCM";
 		break;
 	}
-	if (snd_BUG_ON(ch >= ARRAY_SIZE(channel_name)))
+	if (ch >= ARRAY_SIZE(channel_name)) {
+		snd_BUG();
 		return "PCM";
+	}
 
 	return channel_name[ch];
 }