memory: fsl_ifc: fix leak of IO mapping on probe failure

On probe error the driver should unmap the IO memory.  Smatch reports:

  drivers/memory/fsl_ifc.c:298 fsl_ifc_ctrl_probe() warn: 'fsl_ifc_ctrl_dev->gregs' not released on lines: 298.

Fixes: a20cbdeffc ("powerpc/fsl: Add support for Integrated Flash Controller")
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Link: https://lore.kernel.org/r/20210527154322.81253-1-krzysztof.kozlowski@canonical.com

drivers/memory/fsl_ifc.c

@@ -219,8 +219,7 @@ static int fsl_ifc_ctrl_probe(struct platform_device *dev)
 	fsl_ifc_ctrl_dev->gregs = of_iomap(dev->dev.of_node, 0);
 	if (!fsl_ifc_ctrl_dev->gregs) {
 		dev_err(&dev->dev, "failed to get memory region\n");
-		ret = -ENODEV;
-		goto err;
+		return -ENODEV;
 	}
 
 	if (of_property_read_bool(dev->dev.of_node, "little-endian")) {
@@ -295,6 +294,7 @@ err_irq:
 	free_irq(fsl_ifc_ctrl_dev->irq, fsl_ifc_ctrl_dev);
 	irq_dispose_mapping(fsl_ifc_ctrl_dev->irq);
 err:
+	iounmap(fsl_ifc_ctrl_dev->gregs);
 	return ret;
 }