[patch] drm/virtio: checking for NULL instead of IS_ERR

[Dan Carpenter]

virtio_gpu_alloc_object() returns an error pointer, it never returns
NULL.

Fixes: dc5698e80cf7 ('Add virtio gpu driver.')
Signed-off-by: Dan Carpenter <dan.carpenter at oracle.com>

diff --git a/drivers/gpu/drm/virtio/virtgpu_fb.c 
b/drivers/gpu/drm/virtio/virtgpu_fb.c
index 25bf333..df198d9 100644
--- a/drivers/gpu/drm/virtio/virtgpu_fb.c
+++ b/drivers/gpu/drm/virtio/virtgpu_fb.c
@@ -299,8 +299,8 @@ static int virtio_gpufb_create(struct drm_fb_helper *helper,

        size = mode_cmd.pitches[0] * mode_cmd.height;
        obj = virtio_gpu_alloc_object(dev, size, false, true);
-       if (!obj)
-               return -ENOMEM;
+       if (IS_ERR(obj))
+               return PTR_ERR(obj);

        virtio_gpu_resource_id_get(vgdev, &resid);
        virtio_gpu_cmd_create_resource(vgdev, resid, format,