USB: serial: quatech2: fix up unneeded printk() call

It should be calling dev_err() instead of printk(KERN_INFO...) so this
change fixes that up properly.

Cc: Bill Pemberton <wfp5p@virginia.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/serial/quatech2.c

@@ -1087,7 +1087,7 @@ static int qt2_write(struct tty_struct *tty,
 	data = write_urb->transfer_buffer;
 	spin_lock_irqsave(&port_priv->urb_lock, flags);
 	if (port_priv->urb_in_use == true) {
-		printk(KERN_INFO "qt2_write - urb is in use\n");
+		dev_err(&port->dev, "qt2_write - urb is in use\n");
 		goto write_out;
 	}