remove tgame_mode::LINGER_SP and tgame_mode::LINGER_MP

they already had the same effect so i merged both options into just
tgame_mode::LINGER

src/game_display.hpp

@@ -214,8 +214,7 @@ public:
 	 */
 	enum tgame_mode {
 		RUNNING,         /**< no linger overlay, show fog and shroud. */
-		LINGER_SP,       /**< linger overlay, show fog and shroud. */
-		LINGER_MP };     /**< linger overlay, show fog and shroud. */
+		LINGER };     /**< linger overlay, show fog and shroud. */
 
 	void set_game_mode(const tgame_mode game_mode);
 

src/playmp_controller.cpp

@@ -238,7 +238,7 @@ void playmp_controller::linger()
 	linger_ = true;
 	// If we need to set the status depending on the completion state
 	// we're needed here.
-	gui_->set_game_mode(game_display::LINGER_MP);
+	gui_->set_game_mode(game_display::LINGER);
 	// End all unit moves
 	gamestate().board_.set_all_units_user_end_turn();
 

src/playsingle_controller.cpp

@@ -452,7 +452,7 @@ void playsingle_controller::linger()
 
 	// If we need to set the status depending on the completion state
 	// the key to it is here.
-	gui_->set_game_mode(game_display::LINGER_SP);
+	gui_->set_game_mode(game_display::LINGER);
 
 	// change the end-turn button text to its alternate label
 	gui_->get_theme().refresh_title2("button-endturn", "title2");