ALSA: aoa: Replace sprintf() with sysfs_emit()

For sysfs outputs, it's safer to use a new helper, sysfs_emit(),
instead of the raw sprintf() & co.  This patch replaces such sprintf()
calls with sysfs_emit() while simplifying the open code in
modalias_show(); as modalias[] is a NUL-terminated string, we can pass
it straightly to a printf() argument.

Link: https://lore.kernel.org/r/20220801165639.26030-3-tiwai@suse.deSigned-off-by: Takashi Iwai <tiwai@suse.de>

sound/aoa/soundbus/sysfs.c

@@ -10,19 +10,13 @@ static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
 {
 	struct soundbus_dev *sdev = to_soundbus_device(dev);
 	struct platform_device *of = &sdev->ofdev;
-	int length;
 
-	if (*sdev->modalias) {
-		strscpy(buf, sdev->modalias, sizeof(sdev->modalias) + 1);
-		strcat(buf, "\n");
-		length = strlen(buf);
-	} else {
-		length = sprintf(buf, "of:N%pOFn%c%s\n",
-				 of->dev.of_node, 'T',
-                                 of_node_get_device_type(of->dev.of_node));
-	}
-
-	return length;
+	if (*sdev->modalias)
+		return sysfs_emit(buf, "%s\n", sdev->modalias);
+	else
+		return sysfs_emit(buf, "of:N%pOFn%c%s\n",
+				  of->dev.of_node, 'T',
+				  of_node_get_device_type(of->dev.of_node));
 }
 static DEVICE_ATTR_RO(modalias);
 
@@ -32,7 +26,7 @@ static ssize_t name_show(struct device *dev,
 	struct soundbus_dev *sdev = to_soundbus_device(dev);
 	struct platform_device *of = &sdev->ofdev;
 
-	return sprintf(buf, "%pOFn\n", of->dev.of_node);
+	return sysfs_emit(buf, "%pOFn\n", of->dev.of_node);
 }
 static DEVICE_ATTR_RO(name);
 
@@ -42,7 +36,7 @@ static ssize_t type_show(struct device *dev,
 	struct soundbus_dev *sdev = to_soundbus_device(dev);
 	struct platform_device *of = &sdev->ofdev;
 
-	return sprintf(buf, "%s\n", of_node_get_device_type(of->dev.of_node));
+	return sysfs_emit(buf, "%s\n", of_node_get_device_type(of->dev.of_node));
 }
 static DEVICE_ATTR_RO(type);