ALSA: usb-audio: scarlett2: Don't copy struct scarlett2_config

scarlett2_usb_set_config() and scarlett2_usb_get_config() were copying
struct scarlett2_config. Use a pointer instead.
Signed-off-by: Geoffrey D. Bennett <g@b4.vu>
Link: https://lore.kernel.org/r/20210620164648.GA9231@m.b4.vuSigned-off-by: Takashi Iwai <tiwai@suse.de>

sound/usb/mixer_scarlett_gen2.c

@@ -706,8 +706,8 @@ static int scarlett2_usb_set_config(
 	struct usb_mixer_interface *mixer,
 	int config_item_num, int index, int value)
 {
-	const struct scarlett2_config config_item =
-	       scarlett2_config_items[config_item_num];
+	const struct scarlett2_config *config_item =
+	       &scarlett2_config_items[config_item_num];
 	struct {
 		__le32 offset;
 		__le32 bytes;
@@ -721,17 +721,17 @@ static int scarlett2_usb_set_config(
 	cancel_delayed_work_sync(&private->work);
 
 	/* Send the configuration parameter data */
-	req.offset = cpu_to_le32(config_item.offset + index * config_item.size);
-	req.bytes = cpu_to_le32(config_item.size);
+	req.offset = cpu_to_le32(config_item->offset + index * config_item->size);
+	req.bytes = cpu_to_le32(config_item->size);
 	req.value = cpu_to_le32(value);
 	err = scarlett2_usb(mixer, SCARLETT2_USB_SET_DATA,
-			    &req, sizeof(u32) * 2 + config_item.size,
+			    &req, sizeof(u32) * 2 + config_item->size,
 			    NULL, 0);
 	if (err < 0)
 		return err;
 
 	/* Activate the change */
-	req2 = cpu_to_le32(config_item.activate);
+	req2 = cpu_to_le32(config_item->activate);
 	err = scarlett2_usb(mixer, SCARLETT2_USB_DATA_CMD,
 			    &req2, sizeof(req2), NULL, 0);
 	if (err < 0)
@@ -764,11 +764,11 @@ static int scarlett2_usb_get_config(
 	struct usb_mixer_interface *mixer,
 	int config_item_num, int count, void *buf)
 {
-	const struct scarlett2_config config_item =
-	       scarlett2_config_items[config_item_num];
-	int size = config_item.size * count;
+	const struct scarlett2_config *config_item =
+		&scarlett2_config_items[config_item_num];
+	int size = config_item->size * count;
 
-	return scarlett2_usb_get(mixer, config_item.offset, buf, size);
+	return scarlett2_usb_get(mixer, config_item->offset, buf, size);
 }
 
 /* Send a USB message to get volume status; result placed in *buf */