sound: seq_midi_event: fix decoding of (N)RPN events

When decoding (N)RPN sequencer events into raw MIDI commands, the
extra_decode_xrpn() function had accidentally swapped the MSB and LSB
controller values of both the parameter number and the data value.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Cc: <stable@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/core/seq/seq_midi_event.c

@@ -504,10 +504,10 @@ static int extra_decode_xrpn(struct snd_midi_event *dev, unsigned char *buf,
 	if (dev->nostat && count < 12)
 		return -ENOMEM;
 	cmd = MIDI_CMD_CONTROL|(ev->data.control.channel & 0x0f);
-	bytes[0] = ev->data.control.param & 0x007f;
-	bytes[1] = (ev->data.control.param & 0x3f80) >> 7;
-	bytes[2] = ev->data.control.value & 0x007f;
-	bytes[3] = (ev->data.control.value & 0x3f80) >> 7;
+	bytes[0] = (ev->data.control.param & 0x3f80) >> 7;
+	bytes[1] = ev->data.control.param & 0x007f;
+	bytes[2] = (ev->data.control.value & 0x3f80) >> 7;
+	bytes[3] = ev->data.control.value & 0x007f;
 	if (cmd != dev->lastcmd && !dev->nostat) {
 		if (count < 9)
 			return -ENOMEM;