ALSA: usb-audio: scarlett2: Merge common line in capture strings

Use a common sprintf() format for the mixer element names generated in
scarlett2_add_line_in_ctls() in preparation for more of them.
Signed-off-by: Geoffrey D. Bennett <g@b4.vu>
Link: https://lore.kernel.org/r/d91dce45ac75a541c21f47540ecbda24bd83f68c.1624294591.git.g@b4.vuSigned-off-by: Takashi Iwai <tiwai@suse.de>

sound/usb/mixer_scarlett_gen2.c

@@ -1660,10 +1660,11 @@ static int scarlett2_add_line_in_ctls(struct usb_mixer_interface *mixer)
 	const struct scarlett2_device_info *info = private->info;
 	int err, i;
 	char s[SNDRV_CTL_ELEM_ID_NAME_MAXLEN];
+	const char *fmt = "Line In %d %s Capture %s";
 
 	/* Add input level (line/inst) controls */
 	for (i = 0; i < info->level_input_count; i++) {
-		snprintf(s, sizeof(s), "Line In %d Level Capture Enum", i + 1);
+		snprintf(s, sizeof(s), fmt, i + 1, "Level", "Enum");
 		err = scarlett2_add_new_ctl(mixer, &scarlett2_level_enum_ctl,
 					    i, 1, s, NULL);
 		if (err < 0)
@@ -1672,7 +1673,7 @@ static int scarlett2_add_line_in_ctls(struct usb_mixer_interface *mixer)
 
 	/* Add input pad controls */
 	for (i = 0; i < info->pad_input_count; i++) {
-		snprintf(s, sizeof(s), "Line In %d Pad Capture Switch", i + 1);
+		snprintf(s, sizeof(s), fmt, i + 1, "Pad", "Switch");
 		err = scarlett2_add_new_ctl(mixer, &scarlett2_pad_ctl,
 					    i, 1, s, NULL);
 		if (err < 0)