mtd: spi-nor: nxp-spifi: release flash_np in nxp_spifi_probe()

nxp_spifi_probe() increments refcnt of SPI flash device node by
of_get_next_available_child() and leaves it undecremented on both
successful and error paths.

Found by Linux Driver Verification project (linuxtesting.org).
Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>

drivers/mtd/spi-nor/nxp-spifi.c

@@ -436,6 +436,7 @@ static int nxp_spifi_probe(struct platform_device *pdev)
 	}
 
 	ret = nxp_spifi_setup_flash(spifi, flash_np);
+	of_node_put(flash_np);
 	if (ret) {
 		dev_err(&pdev->dev, "unable to setup flash chip\n");
 		goto dis_clks;