drm/i915: Introduce some local intel_dp variables

The drrs code dereferences mode->vrefresh via some really long chain
of structures/pointers. Couldn't get coccinelle to see through all
that so let's add some local variables to help it.

Reviewed-by: Emil Velikov <[e-mail]>
Signed-off-by: Ville Syrjälä <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]

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

···
 void intel_edp_drrs_invalidate(struct drm_i915_private *dev_priv,
 			       unsigned int frontbuffer_bits)
 {
+	struct intel_dp *intel_dp;
 	struct drm_crtc *crtc;
 	enum pipe pipe;
 
···
 	cancel_delayed_work(&dev_priv->drrs.work);
 
 	mutex_lock(&dev_priv->drrs.mutex);
-	if (!dev_priv->drrs.dp) {
+
+	intel_dp = dev_priv->drrs.dp;
+	if (!intel_dp) {
 		mutex_unlock(&dev_priv->drrs.mutex);
 		return;
 	}
 
-	crtc = dp_to_dig_port(dev_priv->drrs.dp)->base.base.crtc;
+	crtc = dp_to_dig_port(intel_dp)->base.base.crtc;
 	pipe = to_intel_crtc(crtc)->pipe;
 
 	frontbuffer_bits &= INTEL_FRONTBUFFER_ALL_MASK(pipe);
···
 	/* invalidate means busy screen hence upclock */
 	if (frontbuffer_bits && dev_priv->drrs.refresh_rate_type == DRRS_LOW_RR)
 		intel_dp_set_drrs_state(dev_priv, to_intel_crtc(crtc)->config,
-			dev_priv->drrs.dp->attached_connector->panel.fixed_mode->vrefresh);
+					intel_dp->attached_connector->panel.fixed_mode->vrefresh);
 
 	mutex_unlock(&dev_priv->drrs.mutex);
 }
···
 void intel_edp_drrs_flush(struct drm_i915_private *dev_priv,
 			  unsigned int frontbuffer_bits)
 {
+	struct intel_dp *intel_dp;
 	struct drm_crtc *crtc;
 	enum pipe pipe;
 
···
 	cancel_delayed_work(&dev_priv->drrs.work);
 
 	mutex_lock(&dev_priv->drrs.mutex);
-	if (!dev_priv->drrs.dp) {
+
+	intel_dp = dev_priv->drrs.dp;
+	if (!intel_dp) {
 		mutex_unlock(&dev_priv->drrs.mutex);
 		return;
 	}
 
-	crtc = dp_to_dig_port(dev_priv->drrs.dp)->base.base.crtc;
+	crtc = dp_to_dig_port(intel_dp)->base.base.crtc;
 	pipe = to_intel_crtc(crtc)->pipe;
 
 	frontbuffer_bits &= INTEL_FRONTBUFFER_ALL_MASK(pipe);
···
 	/* flush means busy screen hence upclock */
 	if (frontbuffer_bits && dev_priv->drrs.refresh_rate_type == DRRS_LOW_RR)
 		intel_dp_set_drrs_state(dev_priv, to_intel_crtc(crtc)->config,
-				dev_priv->drrs.dp->attached_connector->panel.fixed_mode->vrefresh);
+					intel_dp->attached_connector->panel.fixed_mode->vrefresh);
 
 	/*
 	 * flush also means no more activity hence schedule downclock, if all