hwrng: atmel - 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: NJingoo Han <jg1.han@samsung.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

drivers/char/hw_random/atmel-rng.c

@@ -108,8 +108,6 @@ static int atmel_trng_remove(struct platform_device *pdev)
 	clk_disable(trng->clk);
 	clk_put(trng->clk);
 
-	platform_set_drvdata(pdev, NULL);
-
 	return 0;
 }