rtc: rtc-mc13xxx: remove unnecessary platform_set_drvdata()

The driver core clears the driver data to NULL after device_release or
on probe failure, since commit 0998d063 ("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: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/rtc/rtc-mc13xxx.c

@@ -370,8 +370,6 @@ static int __init mc13xxx_rtc_probe(struct platform_device *pdev)
 err_reset_irq_request:
 
 		mc13xxx_unlock(mc13xxx);
-
-		platform_set_drvdata(pdev, NULL);
 	}
 
 	return ret;
@@ -389,8 +387,6 @@ static int __exit mc13xxx_rtc_remove(struct platform_device *pdev)
 
 	mc13xxx_unlock(priv->mc13xxx);
 
-	platform_set_drvdata(pdev, NULL);
-
 	return 0;
 }