drm/i915: Get rid of crtc->config dereference in intel_dp_retrain_link

We're already using crtc_state here and made sure no modeset is
occurring by looking at conn_state->commit->hw_done, so there's
no need to dereference crtc->config.
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181004094604.2646-12-maarten.lankhorst@linux.intel.com

drivers/gpu/drm/i915/intel_dp.c

@@ -4420,7 +4420,7 @@ int intel_dp_retrain_link(struct intel_encoder *encoder,
 
 	/* Suppress underruns caused by re-training */
 	intel_set_cpu_fifo_underrun_reporting(dev_priv, crtc->pipe, false);
-	if (crtc->config->has_pch_encoder)
+	if (crtc_state->has_pch_encoder)
 		intel_set_pch_fifo_underrun_reporting(dev_priv,
 						      intel_crtc_pch_transcoder(crtc), false);
 
@@ -4431,7 +4431,7 @@ int intel_dp_retrain_link(struct intel_encoder *encoder,
 	intel_wait_for_vblank(dev_priv, crtc->pipe);
 
 	intel_set_cpu_fifo_underrun_reporting(dev_priv, crtc->pipe, true);
-	if (crtc->config->has_pch_encoder)
+	if (crtc_state->has_pch_encoder)
 		intel_set_pch_fifo_underrun_reporting(dev_priv,
 						      intel_crtc_pch_transcoder(crtc), true);