hwrng: bcm2835 - remove redundant null check

clk_prepare_enable() and clk_disable_unprepare() will check
NULL clock parameter, so It is not necessary to add additional checks.

Signed-off-by: Tian Tao <[e-mail]>
Acked-by: Florian Fainelli <[e-mail]>
Signed-off-by: Herbert Xu <[e-mail]>

drivers/char/hw_random/bcm2835-rng.c

···
 	int ret = 0;
 	u32 val;
 
-	if (!IS_ERR(priv->clk)) {
-		ret = clk_prepare_enable(priv->clk);
-		if (ret)
-			return ret;
-	}
+	ret = clk_prepare_enable(priv->clk);
+	if (ret)
+		return ret;
 
 	if (priv->mask_interrupts) {
 		/* mask the interrupt */
···
 	/* disable rng hardware */
 	rng_writel(priv, 0, RNG_CTRL);
 
-	if (!IS_ERR(priv->clk))
-		clk_disable_unprepare(priv->clk);
+	clk_disable_unprepare(priv->clk);
 }
 
 struct bcm2835_rng_of_data {
···
 		return PTR_ERR(priv->base);
 
 	/* Clock is optional on most platforms */
-	priv->clk = devm_clk_get(dev, NULL);
-	if (PTR_ERR(priv->clk) == -EPROBE_DEFER)
-		return -EPROBE_DEFER;
+	priv->clk = devm_clk_get_optional(dev, NULL);
+	if (IS_ERR(priv->clk))
+		return PTR_ERR(priv->clk);
 
 	priv->rng.name = pdev->name;
 	priv->rng.init = bcm2835_rng_init;