drm/i915: Use drm_rect_translate_to()

Use the newly introduced drm_rect_translate_to() instead
of hand rolling it.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190930134214.24702-3-ville.syrjala@linux.intel.comReviewed-by: Jani Nikula <jani.nikula@intel.com>

drivers/gpu/drm/i915/display/intel_display.c

@@ -3476,9 +3476,8 @@ static int skl_check_main_surface(struct intel_plane_state *plane_state)
 	 * Put the final coordinates back so that the src
 	 * coordinate checks will see the right values.
 	 */
-	drm_rect_translate(&plane_state->base.src,
-			   (x << 16) - plane_state->base.src.x1,
-			   (y << 16) - plane_state->base.src.y1);
+	drm_rect_translate_to(&plane_state->base.src,
+			      x << 16, y << 16);
 
 	return 0;
 }
@@ -3700,9 +3699,8 @@ int i9xx_check_plane_surface(struct intel_plane_state *plane_state)
 	 * Put the final coordinates back so that the src
 	 * coordinate checks will see the right values.
 	 */
-	drm_rect_translate(&plane_state->base.src,
-			   (src_x << 16) - plane_state->base.src.x1,
-			   (src_y << 16) - plane_state->base.src.y1);
+	drm_rect_translate_to(&plane_state->base.src,
+			      src_x << 16, src_y << 16);
 
 	/* HSW/BDW do this automagically in hardware */
 	if (!IS_HASWELL(dev_priv) && !IS_BROADWELL(dev_priv)) {