ALSA: usb: Constify snd_rawmidi_ops

Now snd_rawmidi_ops is maintained as a const pointer in snd_rawmidi,
we can constify the definitions.
Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/usb/6fire/midi.c

@@ -139,14 +139,14 @@ static void usb6fire_midi_in_trigger(
 	spin_unlock_irqrestore(&rt->in_lock, flags);
 }
 
-static struct snd_rawmidi_ops out_ops = {
+static const struct snd_rawmidi_ops out_ops = {
 	.open = usb6fire_midi_out_open,
 	.close = usb6fire_midi_out_close,
 	.trigger = usb6fire_midi_out_trigger,
 	.drain = usb6fire_midi_out_drain
 };
 
-static struct snd_rawmidi_ops in_ops = {
+static const struct snd_rawmidi_ops in_ops = {
 	.open = usb6fire_midi_in_open,
 	.close = usb6fire_midi_in_close,
 	.trigger = usb6fire_midi_in_trigger

sound/usb/bcd2000/bcd2000.c

@@ -252,13 +252,13 @@ static void bcd2000_input_complete(struct urb *urb)
 			__func__, ret);
 }
 
-static struct snd_rawmidi_ops bcd2000_midi_output = {
+static const struct snd_rawmidi_ops bcd2000_midi_output = {
 	.open =    bcd2000_midi_output_open,
 	.close =   bcd2000_midi_output_close,
 	.trigger = bcd2000_midi_output_trigger,
 };
 
-static struct snd_rawmidi_ops bcd2000_midi_input = {
+static const struct snd_rawmidi_ops bcd2000_midi_input = {
 	.open =    bcd2000_midi_input_open,
 	.close =   bcd2000_midi_input_close,
 	.trigger = bcd2000_midi_input_trigger,

sound/usb/caiaq/midi.c

@@ -102,14 +102,14 @@ static void snd_usb_caiaq_midi_output_trigger(struct snd_rawmidi_substream *subs
 }
 
 
-static struct snd_rawmidi_ops snd_usb_caiaq_midi_output =
+static const struct snd_rawmidi_ops snd_usb_caiaq_midi_output =
 {
 	.open =		snd_usb_caiaq_midi_output_open,
 	.close =	snd_usb_caiaq_midi_output_close,
 	.trigger =      snd_usb_caiaq_midi_output_trigger,
 };
 
-static struct snd_rawmidi_ops snd_usb_caiaq_midi_input =
+static const struct snd_rawmidi_ops snd_usb_caiaq_midi_input =
 {
 	.open =		snd_usb_caiaq_midi_input_open,
 	.close =	snd_usb_caiaq_midi_input_close,

sound/usb/line6/midi.c

@@ -200,14 +200,14 @@ static void line6_midi_input_trigger(struct snd_rawmidi_substream *substream,
 		line6->line6midi->substream_receive = NULL;
 }
 
-static struct snd_rawmidi_ops line6_midi_output_ops = {
+static const struct snd_rawmidi_ops line6_midi_output_ops = {
 	.open = line6_midi_output_open,
 	.close = line6_midi_output_close,
 	.trigger = line6_midi_output_trigger,
 	.drain = line6_midi_output_drain,
 };
 
-static struct snd_rawmidi_ops line6_midi_input_ops = {
+static const struct snd_rawmidi_ops line6_midi_input_ops = {
 	.open = line6_midi_input_open,
 	.close = line6_midi_input_close,
 	.trigger = line6_midi_input_trigger,

sound/usb/midi.c

@@ -1234,14 +1234,14 @@ static void snd_usbmidi_input_trigger(struct snd_rawmidi_substream *substream,
 		clear_bit(substream->number, &umidi->input_triggered);
 }
 
-static struct snd_rawmidi_ops snd_usbmidi_output_ops = {
+static const struct snd_rawmidi_ops snd_usbmidi_output_ops = {
 	.open = snd_usbmidi_output_open,
 	.close = snd_usbmidi_output_close,
 	.trigger = snd_usbmidi_output_trigger,
 	.drain = snd_usbmidi_output_drain,
 };
 
-static struct snd_rawmidi_ops snd_usbmidi_input_ops = {
+static const struct snd_rawmidi_ops snd_usbmidi_input_ops = {
 	.open = snd_usbmidi_input_open,
 	.close = snd_usbmidi_input_close,
 	.trigger = snd_usbmidi_input_trigger