drm/i915: Correctly terminate connector iteration

One should use drm_connector_list_iter_end() rather than
drm_connector_list_iter_begin() to terminate the connector
iteration.

Cc: Manasi Navare <manasi.d.navare@intel.com>
Cc: Uma Shankar <uma.shankar@intel.com>
Closes: https://gitlab.freedesktop.org/drm/intel/issues/1278
Fixes: e24bcd34 ("drm/i915/dp: Add all tiled and port sync conns to modeset")
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200221154310.14858-1-ville.syrjala@linux.intel.comReviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Uma Shankar <uma.shankar@intel.com>

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

@@ -6636,7 +6636,7 @@ static int intel_modeset_tile_group(struct intel_atomic_state *state,
 		if (ret)
 			break;
 	}
-	drm_connector_list_iter_begin(&dev_priv->drm, &conn_iter);
+	drm_connector_list_iter_end(&conn_iter);
 
 	return ret;
 }