ALSA: hda - Return the error from get_wcaps_type() for invalid NIDs

When an invalid NID is given, get_wcaps() returns zero as the error,
but get_wcaps_type() takes it as the normal value and returns a bogus
AC_WID_AUD_OUT value.  This confuses the parser.

With this patch, get_wcaps_type() returns -1 when value 0 is given,
i.e. an invalid NID is passed to get_wcaps().

Bugzilla: https://bugzilla.novell.com/show_bug.cgi?id=740118

Cc: <stable@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/pci/hda/hda_proc.c b/sound/pci/hda/hda_proc.c
index 2c981b5..254ab52 100644
--- a/sound/pci/hda/hda_proc.c
+++ b/sound/pci/hda/hda_proc.c
@@ -54,6 +54,8 @@
 		[AC_WID_BEEP] = "Beep Generator Widget",
 		[AC_WID_VENDOR] = "Vendor Defined Widget",
 	};
+	if (wid_value == -1)
+		return "UNKNOWN Widget";
 	wid_value &= 0xf;
 	if (names[wid_value])
 		return names[wid_value];