ALSA: snd-usb: mixer: propagate errors up the call chain

commit 4d7b86c9 upstream.

In check_input_term() and parse_audio_feature_unit(), propagate the
error value that has been returned by a failing function instead of
-EINVAL. That helps cleaning up the error pathes in the mixer.
Signed-off-by: Daniel Mack <zonque@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

sound/usb/mixer.c

@@ -711,8 +711,9 @@ static int check_input_term(struct mixer_build *state, int id, struct usb_audio_
 		case UAC2_CLOCK_SELECTOR: {
 			struct uac_selector_unit_descriptor *d = p1;
 			/* call recursively to retrieve the channel info */
-			if (check_input_term(state, d->baSourceID[0], term) < 0)
-				return -ENODEV;
+			err = check_input_term(state, d->baSourceID[0], term);
+			if (err < 0)
+				return err;
 			term->type = d->bDescriptorSubtype << 16; /* virtual type */
 			term->id = id;
 			term->name = uac_selector_unit_iSelector(d);
@@ -1263,8 +1264,9 @@ static int parse_audio_feature_unit(struct mixer_build *state, int unitid, void
 		return err;
 
 	/* determine the input source type and name */
-	if (check_input_term(state, hdr->bSourceID, &iterm) < 0)
-		return -EINVAL;
+	err = check_input_term(state, hdr->bSourceID, &iterm);
+	if (err < 0)
+		return err;
 
 	master_bits = snd_usb_combine_bytes(bmaControls, csize);
 	/* master configuration quirks */