spi: spi-fsl-qspi: check return value after calling platform_get_resource_byname()

It will cause null-ptr-deref if platform_get_resource_byname() returns NULL,
we need check the return value.

Fixes: 858e26a5 ("spi: spi-fsl-qspi: Reduce devm_ioremap size to 4 times AHB buffer size")
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>
Link: https://lore.kernel.org/r/20220505093954.1285615-1-yangyingliang@huawei.comSigned-off-by: NMark Brown <broonie@kernel.org>

drivers/spi/spi-fsl-qspi.c

@@ -876,6 +876,10 @@ static int fsl_qspi_probe(struct platform_device *pdev)
 
 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
 					"QuadSPI-memory");
+	if (!res) {
+		ret = -EINVAL;
+		goto err_put_ctrl;
+	}
 	q->memmap_phy = res->start;
 	/* Since there are 4 cs, map size required is 4 times ahb_buf_size */
 	q->ahb_addr = devm_ioremap(dev, q->memmap_phy,