clk: bcm2835: fix check of error code returned by devm_ioremap_resource()

The change fixes potential oops while accessing iomem on invalid
address, if devm_ioremap_resource() fails due to some reason.

The devm_ioremap_resource() function returns ERR_PTR() and never
returns NULL, which makes useless a following check for NULL.

Signed-off-by: Vladimir Zapolskiy <vz@mleia.com>
Fixes: 5e63dcc74b30 ("clk: bcm2835: Add a driver for the auxiliary peripheral clock gates")
Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
diff --git a/drivers/clk/bcm/clk-bcm2835-aux.c b/drivers/clk/bcm/clk-bcm2835-aux.c
index e4f89e2..3a177ad 100644
--- a/drivers/clk/bcm/clk-bcm2835-aux.c
+++ b/drivers/clk/bcm/clk-bcm2835-aux.c
@@ -38,8 +38,8 @@
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	reg = devm_ioremap_resource(dev, res);
-	if (!reg)
-		return -ENODEV;
+	if (IS_ERR(reg))
+		return PTR_ERR(reg);
 
 	onecell = devm_kmalloc(dev, sizeof(*onecell), GFP_KERNEL);
 	if (!onecell)