usb: misc: usbsevseg: Use sysfs_match_string() helper

Use sysfs_match_string() helper instead of open coded variant.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/misc/usbsevseg.c

@@ -33,7 +33,7 @@ static const struct usb_device_id id_table[] = {
 MODULE_DEVICE_TABLE(usb, id_table);
 
 /* the different text display modes the device is capable of */
-static char *display_textmodes[] = {"raw", "hex", "ascii", NULL};
+static const char *display_textmodes[] = {"raw", "hex", "ascii"};
 
 struct usb_sevsegdev {
 	struct usb_device *udev;
@@ -280,7 +280,7 @@ static ssize_t show_attr_textmode(struct device *dev,
 
 	buf[0] = 0;
 
-	for (i = 0; display_textmodes[i]; i++) {
+	for (i = 0; i < ARRAY_SIZE(display_textmodes); i++) {
 		if (mydev->textmode == i) {
 			strcat(buf, " [");
 			strcat(buf, display_textmodes[i]);
@@ -304,15 +304,13 @@ static ssize_t set_attr_textmode(struct device *dev,
 	struct usb_sevsegdev *mydev = usb_get_intfdata(intf);
 	int i;
 
-	for (i = 0; display_textmodes[i]; i++) {
-		if (sysfs_streq(display_textmodes[i], buf)) {
+	i = sysfs_match_string(display_textmodes, buf);
+	if (i < 0)
+		return i;
+
 	mydev->textmode = i;
 	update_display_visual(mydev, GFP_KERNEL);
 	return count;
-		}
-	}
-
-	return -EINVAL;
 }
 
 static DEVICE_ATTR(textmode, S_IRUGO | S_IWUSR, show_attr_textmode, set_attr_textmode);