spi: topcliff-pch: fix error return code in pch_spi_probe()

Fix to return -ENOMEM in the platform_device_alloc() error handling
case instead of 0, as done elsewhere in this function.
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

drivers/spi/spi-topcliff-pch.c

@@ -1667,6 +1667,7 @@ static int pch_spi_probe(struct pci_dev *pdev,
 		pd_dev = platform_device_alloc("pch-spi", i);
 		if (!pd_dev) {
 			dev_err(&pdev->dev, "platform_device_alloc failed\n");
+			retval = -ENOMEM;
 			goto err_platform_device;
 		}
 		pd_dev_save->pd_save[i] = pd_dev;