gpio: vx855: remove unnecessary platform_set_drvdata()

The driver core clears the driver data to NULL after device_release
or on probe failure, since commit 0998d0631001288a5974afc0b2a5f568bcdecb4d
(device-core: Ensure drvdata = NULL when no driver is bound).
Thus, it is not needed to manually clear the device driver data to NULL.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/drivers/gpio/gpio-vx855.c b/drivers/gpio/gpio-vx855.c
index 2b7252c..cddfa22 100644
--- a/drivers/gpio/gpio-vx855.c
+++ b/drivers/gpio/gpio-vx855.c
@@ -279,7 +279,6 @@
 		release_region(res_gpi->start, resource_size(res_gpi));
 	if (vg->gpo_reserved)
 		release_region(res_gpi->start, resource_size(res_gpo));
-	platform_set_drvdata(pdev, NULL);
 	kfree(vg);
 	return ret;
 }
@@ -301,7 +300,6 @@
 		release_region(res->start, resource_size(res));
 	}
 
-	platform_set_drvdata(pdev, NULL);
 	kfree(vg);
 	return 0;
 }