USB: serial: remove recourse to generic method

This removes the fallback to the generic method. It is cleaner to
explicitely request it. Introducing this was my mistake. This will
be solved by an explicit test and the driver being allowed to request
what it needs to be done upon resumption.
Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/serial/usb-serial.c

@@ -1229,7 +1229,6 @@ static void fixup_generic(struct usb_serial_driver *device)
 	set_to_generic_if_null(device, read_bulk_callback);
 	set_to_generic_if_null(device, write_bulk_callback);
 	set_to_generic_if_null(device, shutdown);
-	set_to_generic_if_null(device, resume);
 }
 
 int usb_serial_register(struct usb_serial_driver *driver)