USB: small fix in error case of suspend in generic usbserial code

usb:usbserial: fix flags in error case of suspension

suspended flag must be reset in error case
Signed-off-by: Oliver Neukum <oliver@neukum.org>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/serial/usb-serial.c

@@ -1168,8 +1168,10 @@ int usb_serial_suspend(struct usb_interface *intf, pm_message_t message)
 
 	if (serial->type->suspend) {
 		r = serial->type->suspend(serial, message);
-		if (r < 0)
+		if (r < 0) {
+			serial->suspending = 0;
 			goto err_out;
+		}
 	}
 
 	for (i = 0; i < serial->num_ports; ++i) {