drm: Fix confusing debug message in drm_update_vblank_count()

Now that drm_update_vblank_count() can be called even when we're not
about to enable the vblank interrupts we shouldn't print debug messages
stating otherwise.
Signed-off-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/drm_irq.c

@@ -103,7 +103,7 @@ static void drm_update_vblank_count(struct drm_device *dev, int crtc)
 			  crtc, vblank->last, cur_vblank, diff);
 	}
 
-	DRM_DEBUG("enabling vblank interrupts on crtc %d, missed %d\n",
+	DRM_DEBUG("updating vblank count on crtc %d, missed %d\n",
 		  crtc, diff);
 
 	/* Reinitialize corresponding vblank timestamp if high-precision query