ALSA: ump: Correct wrong byte size at converting a UMP System message

A wrong size for UMP_SYSTEM_STATUS_MIDI_TIME_CODE and case
UMP_SYSTEM_STATUS_SONG_SELECT was reported at converting to the legacy
MIDI 1.0 stream.  This patch corrects the value.

Fixes: 0b5288f ("ALSA: ump: Add legacy raw MIDI support")
Link: https://lore.kernel.org/r/20230628094352.15754-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/core/ump_convert.c

@@ -73,7 +73,7 @@ static int cvt_ump_system_to_legacy(u32 data, unsigned char *buf)
 	case UMP_SYSTEM_STATUS_MIDI_TIME_CODE:
 	case UMP_SYSTEM_STATUS_SONG_SELECT:
 		buf[1] = (data >> 8) & 0x7f;
-		return 1;
+		return 2;
 	case UMP_SYSTEM_STATUS_SONG_POSITION:
 		buf[1] = (data >> 8) & 0x7f;
 		buf[2] = data & 0x7f;