USB: serial: metro-usb: remove duplicated #include <linux/errno.h>

Signed-off-by: Aleksey Babahin <tamerlan311@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/serial/metro-usb.c

@@ -17,7 +17,6 @@
 #include <linux/tty_flip.h>
 #include <linux/moduleparam.h>
 #include <linux/spinlock.h>
-#include <linux/errno.h>
 #include <linux/uaccess.h>
 #include <linux/usb/serial.h>