mtd: gpmi: fix a dereferencing freed memory error

The patch "490e280a mtd: gpmi-nand: Convert to module_platform_driver()"
introduced a "dereferencing freed memory" error.

This patch fixes it.
Signed-off-by: NHuang Shijie <b32955@freescale.com>
Signed-off-by: NArtem Bityutskiy <artem.bityutskiy@linux.intel.com>

drivers/mtd/nand/gpmi-nand/gpmi-nand.c

@@ -1657,8 +1657,8 @@ static int gpmi_nand_probe(struct platform_device *pdev)
 	release_resources(this);
 exit_acquire_resources:
 	platform_set_drvdata(pdev, NULL);
-	kfree(this);
 	dev_err(this->dev, "driver registration failed: %d\n", ret);
+	kfree(this);
 
 	return ret;
 }