ASoC: wm_adsp: Use scnprintf() for the limited buffer output

snprintf() is a hard-to-use function, it's especially difficult to use
it for concatenating substrings in a buffer with a limited size.
Since snprintf() returns the would-be-output size, not the actual
size, the subsequent use of snprintf() may point to the incorrect
position.

Use scnprintf() instead for fixing such potential errors.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Acked-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20200313130334.9028-1-tiwai@suse.deSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/codecs/wm_adsp.c

@@ -1432,12 +1432,12 @@ static int wm_adsp_create_control(struct wm_adsp *dsp,
 		subname = NULL; /* don't append subname */
 		break;
 	case 2:
-		ret = snprintf(name, SNDRV_CTL_ELEM_ID_NAME_MAXLEN,
+		ret = scnprintf(name, SNDRV_CTL_ELEM_ID_NAME_MAXLEN,
 				"%s%c %.12s %x", dsp->name, *region_name,
 				wm_adsp_fw_text[dsp->fw], alg_region->alg);
 		break;
 	default:
-		ret = snprintf(name, SNDRV_CTL_ELEM_ID_NAME_MAXLEN,
+		ret = scnprintf(name, SNDRV_CTL_ELEM_ID_NAME_MAXLEN,
 				"%s %.12s %x", dsp->name,
 				wm_adsp_fw_text[dsp->fw], alg_region->alg);
 		break;