drm/i915: Stop consulting plane->fb

We want to get rid of plane->fb on atomic drivers. Stop looking at it.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180322152313.6561-10-ville.syrjala@linux.intel.com
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 3b48fd2..54d4c36 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -2824,7 +2824,7 @@ intel_find_initial_plane_obj(struct intel_crtc *intel_crtc,
 			continue;
 
 		if (intel_plane_ggtt_offset(state) == plane_config->base) {
-			fb = c->primary->fb;
+			fb = state->base.fb;
 			drm_framebuffer_get(fb);
 			goto valid_fb;
 		}