class_create() and class_device_create() return error code as a pointer on
failure.  These return values need to be checked by IS_ERR().
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Dave Airlie <airlied@linux.ie>
        int err;
 
        class = class_create(owner, name);
-       if (!class) {
-               err = -ENOMEM;
+       if (IS_ERR(class)) {
+               err = PTR_ERR(class);
                goto err_out;
        }
 
                                        MKDEV(DRM_MAJOR, head->minor),
                                        &(head->dev->pdev)->dev,
                                        "card%d", head->minor);
-       if (!class_dev) {
-               err = -ENOMEM;
+       if (IS_ERR(class_dev)) {
+               err = PTR_ERR(class_dev);
                goto err_out;
        }