clk: keystone: pll: fix a couple NULL vs IS_ERR() checks

The clk_register_divider() and clk_register_mux() functions returns
error pointers on error but this code checks for NULL.  Fix that.

Fixes: b9e0d40 ("clk: keystone: add Keystone PLL clock driver")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Link: https://lore.kernel.org/r/d9da4c97-0da9-499f-9a21-1f8e3f148dc1@moroto.mountain
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

Author: Dan Carpenter

drivers/clk/keystone/pll.c

@@ -281,12 +281,13 @@ static void __init of_pll_div_clk_init(struct device_node *node)
 
 	clk = clk_register_divider(NULL, clk_name, parent_name, 0, reg, shift,
 				 mask, 0, NULL);
-	if (clk) {
-		of_clk_add_provider(node, of_clk_src_simple_get, clk);
-	} else {
+	if (IS_ERR(clk)) {
 		pr_err("%s: error registering divider %s\n", __func__, clk_name);
 		iounmap(reg);
+		return;
 	}
+
+	of_clk_add_provider(node, of_clk_src_simple_get, clk);
 }
 CLK_OF_DECLARE(pll_divider_clock, "ti,keystone,pll-divider-clock", of_pll_div_clk_init);
 
@@ -328,10 +329,12 @@ static void __init of_pll_mux_clk_init(struct device_node *node)
 	clk = clk_register_mux(NULL, clk_name, (const char **)&parents,
 				ARRAY_SIZE(parents) , 0, reg, shift, mask,
 				0, NULL);
-	if (clk)
-		of_clk_add_provider(node, of_clk_src_simple_get, clk);
-	else
+	if (IS_ERR(clk)) {
 		pr_err("%s: error registering mux %s\n", __func__, clk_name);
+		return;
+	}
+
+	of_clk_add_provider(node, of_clk_src_simple_get, clk);
 }
 CLK_OF_DECLARE(pll_mux_clock, "ti,keystone,pll-mux-clock", of_pll_mux_clk_init);