raw/cnxk_gpio: stop device once tests are complete

Started device should eventually be stopped.

Fixes: 0e6557b448 ("raw/cnxk_gpio: add self test")

Signed-off-by: Tomasz Duszynski <tduszynski@marvell.com>
Reviewed-by: Jerin Jacob <jerinj@marvell.com>

drivers/raw/cnxk_gpio/cnxk_gpio_selftest.c

@@ -390,6 +390,7 @@ cnxk_gpio_selftest(uint16_t dev_id)
 
 out:
 	close(fd);
+	rte_rawdev_stop(dev_id);
 
 	return ret;
 }