drm/i915/mst: remove crtc_state->pbn

The crtc_state->pbn member is only used as a temporary variable within
mst_stream_find_vcpi_slots_for_bpp(). Remove it as unnecessary.

Suggested-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/726aaadbd425057dfd854e42417bcf8d69b769d3.1735912293.git.jani.nikula@intel.com

Author: jnikula

drivers/gpu/drm/i915/display/intel_display_types.h

@@ -1160,8 +1160,6 @@ struct intel_crtc_state {
 
 	bool double_wide;
 
-	int pbn;
-
 	struct intel_crtc_scaler_state scaler_state;
 
 	/* w/a for waiting 2 vblanks during crtc enable */

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

@@ -321,14 +321,13 @@ static int mst_stream_find_vcpi_slots_for_bpp(struct intel_dp *intel_dp,
 		 * first branch device's link also applies here.
 		 */
 		pbn.full = remote_tu * mst_state->pbn_div.full;
-		crtc_state->pbn = dfixed_trunc(pbn);
 
 		drm_WARN_ON(display->drm, remote_tu < crtc_state->dp_m_n.tu);
 		crtc_state->dp_m_n.tu = remote_tu;
 
 		slots = drm_dp_atomic_find_time_slots(state, &intel_dp->mst_mgr,
 						      connector->port,
-						      crtc_state->pbn);
+						      dfixed_trunc(pbn));
 		if (slots == -EDEADLK)
 			return slots;