[PATCH next] drm/sysfb: Fix a NULL vs IS_ERR() bug

[Dan Carpenter]

The drm_atomic_get_crtc_state() function never returns NULL, it returns
error pointers.  Update the error checking to match.

Fixes: cb71de092553 ("drm/sysfb: Lookup blit function during atomic check")
Signed-off-by: Dan Carpenter <dan.carpen...@linaro.org>
---
 drivers/gpu/drm/sysfb/drm_sysfb_modeset.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/sysfb/drm_sysfb_modeset.c 
b/drivers/gpu/drm/sysfb/drm_sysfb_modeset.c
index 8517c490e815..d2c4d8f3d4d0 100644
--- a/drivers/gpu/drm/sysfb/drm_sysfb_modeset.c
+++ b/drivers/gpu/drm/sysfb/drm_sysfb_modeset.c
@@ -259,7 +259,7 @@ int drm_sysfb_plane_helper_begin_fb_access(struct drm_plane 
*plane,
        ret = -EINVAL;
 
        crtc_state = drm_atomic_get_crtc_state(plane_state->state, 
plane_state->crtc);
-       if (drm_WARN_ON_ONCE(dev, !crtc_state))
+       if (drm_WARN_ON_ONCE(dev, IS_ERR(crtc_state)))
                goto err_drm_gem_end_shadow_fb_access;
        sysfb_crtc_state = to_drm_sysfb_crtc_state(crtc_state);
 
-- 
2.51.0