hwrng: st - use devm_platform_ioremap_resource() to simplify code

Use devm_platform_ioremap_resource() to simplify the code a bit.
This is detected by coccinelle.
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Reviewed-by: Patrice Chotard <patrice.chotard@st.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/char/hw_random/st-rng.c

@@ -72,7 +72,6 @@ static int st_rng_read(struct hwrng *rng, void *data, size_t max, bool wait)
 static int st_rng_probe(struct platform_device *pdev)
 {
 	struct st_rng_data *ddata;
-	struct resource *res;
 	struct clk *clk;
 	void __iomem *base;
 	int ret;
@@ -81,8 +80,7 @@ static int st_rng_probe(struct platform_device *pdev)
 	if (!ddata)
 		return -ENOMEM;
 
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	base = devm_ioremap_resource(&pdev->dev, res);
+	base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(base))
 		return PTR_ERR(base);