[ALSA] _snd_cmipci_uswitch_put doesn't set zero flags

Playing with spdif output on cmipci i've noticed the SPDO5V option does
not change appropriate bits the register.
The _snd_cmipci_uswitch_put checks the change in flags in wrong way.
If 'active' state of an option corresponds to a _zero_ bits in a hw
register then function fails. The SPDO5V is the sample.
In the most cases 'active' state of option is set through an non-zerio
bits in a register. This case works fine.
The fix attached.
Unfortunately i was unable to change spdif output voltage anyway.
Although the register changes right at least.
From: Timofei V. Bondarenko <tim@ipi.ac.ru>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>

sound/pci/cmipci.c

@@ -2198,7 +2198,8 @@ static int _snd_cmipci_uswitch_put(struct snd_kcontrol *kcontrol,
 		val = inb(cm->iobase + args->reg);
 	else
 		val = snd_cmipci_read(cm, args->reg);
-	change = (val & args->mask) != (ucontrol->value.integer.value[0] ? args->mask : 0);
+	change = (val & args->mask) != (ucontrol->value.integer.value[0] ? 
+			args->mask_on : (args->mask & ~args->mask_on));
 	if (change) {
 		val &= ~args->mask;
 		if (ucontrol->value.integer.value[0])