ALSA: mtpav - Fix initial value for input hwport

Fix the initial value for input hwport.  The old value (-1) may cause
Oops when an realtime MIDI byte is received before the input port is
explicitly given.
Instead, now it's set to the broadcasting as default.
Tested-by: Holger Dehnhardt <dehnhardt@ahdehnhardt.de>
Cc: <stable@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/drivers/mtpav.c

@@ -706,7 +706,6 @@ static int __devinit snd_mtpav_probe(struct platform_device *dev)
 	mtp_card->card = card;
 	mtp_card->irq = -1;
 	mtp_card->share_irq = 0;
-	mtp_card->inmidiport = 0xffffffff;
 	mtp_card->inmidistate = 0;
 	mtp_card->outmidihwport = 0xffffffff;
 	init_timer(&mtp_card->timer);
@@ -719,6 +718,8 @@ static int __devinit snd_mtpav_probe(struct platform_device *dev)
 	if (err < 0)
 		goto __error;
 
+	mtp_card->inmidiport = mtp_card->num_ports + MTPAV_PIDX_BROADCAST;
+
 	err = snd_mtpav_get_ISA(mtp_card);
 	if (err < 0)
 		goto __error;