crypto: atmel - fix checks 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 <[e-mail]>
Fixes: b0e8b3417a62 ("crypto: atmel - use devm_xxx() managed function")
Signed-off-by: Herbert Xu <[e-mail]>

drivers/crypto/atmel-aes.c

···
 	}
 
 	aes_dd->io_base = devm_ioremap_resource(&pdev->dev, aes_res);
-	if (!aes_dd->io_base) {
+	if (IS_ERR(aes_dd->io_base)) {
 		dev_err(dev, "can't ioremap\n");
-		err = -ENOMEM;
+		err = PTR_ERR(aes_dd->io_base);
 		goto res_err;
 	}
 

drivers/crypto/atmel-sha.c

···
 	}
 
 	sha_dd->io_base = devm_ioremap_resource(&pdev->dev, sha_res);
-	if (!sha_dd->io_base) {
+	if (IS_ERR(sha_dd->io_base)) {
 		dev_err(dev, "can't ioremap\n");
-		err = -ENOMEM;
+		err = PTR_ERR(sha_dd->io_base);
 		goto res_err;
 	}
 

drivers/crypto/atmel-tdes.c

···
 	}
 
 	tdes_dd->io_base = devm_ioremap_resource(&pdev->dev, tdes_res);
-	if (!tdes_dd->io_base) {
+	if (IS_ERR(tdes_dd->io_base)) {
 		dev_err(dev, "can't ioremap\n");
-		err = -ENOMEM;
+		err = PTR_ERR(tdes_dd->io_base);
 		goto res_err;
 	}