ALSA: ca0106 - Add missing registrations of vmaster controls

Although the vmaster controls are created, they aren't registered thus
they don't appear in the real world.  Added the missing snd_ctl_add()
calls.

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

sound/pci/ca0106/ca0106_mixer.c

@@ -841,13 +841,19 @@ int __devinit snd_ca0106_mixer(struct snd_ca0106 *emu)
 					      snd_ca0106_master_db_scale);
 	if (!vmaster)
 		return -ENOMEM;
+	err = snd_ctl_add(card, vmaster);
+	if (err < 0)
+		return err;
 	add_slaves(card, vmaster, slave_vols);
 
 	if (emu->details->spi_dac == 1) {
 		vmaster = snd_ctl_make_virtual_master("Master Playback Switch",
 						      NULL);
 		if (!vmaster)
 			return -ENOMEM;
+		err = snd_ctl_add(card, vmaster);
+		if (err < 0)
+			return err;
 		add_slaves(card, vmaster, slave_sws);
 	}
         return 0;