Fix unreserving through a green PBS signal not setting the state to red.

This also had the side effect of failed reservation attempts through
a reserve-through signal leaving the signal erroneously set to green.

src/pathfinder/yapf/yapf_rail.cpp

@@ -119,7 +119,7 @@ private:
 				tile = TILE_ADD(tile, diff);
 			}
 		} else if (tile != m_res_fail_tile || td != m_res_fail_td) {
-			UnreserveRailTrack(tile, TrackdirToTrack(td));
+			UnreserveRailTrackdir(tile, td);
 		}
 		return (tile != m_res_dest || td != m_res_dest_td) && (tile != m_res_fail_tile || td != m_res_fail_td);
 	}