usb: core: lower log level when device is not able to deal with string

USB devices should work just fine when they don't support language id.

Lower the log level so user won't panic in the future.

BugLink: https://bugs.launchpad.net/bugs/1729618
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/core/message.c

@@ -776,7 +776,7 @@ static int usb_get_langid(struct usb_device *dev, unsigned char *tbuf)
 	 * deal with strings at all. Set string_langid to -1 in order to
 	 * prevent any string to be retrieved from the device */
 	if (err < 0) {
-		dev_err(&dev->dev, "string descriptor 0 read error: %d\n",
+		dev_info(&dev->dev, "string descriptor 0 read error: %d\n",
 					err);
 		dev->string_langid = -1;
 		return -EPIPE;