Get rid of unnecessary roomname logic

Just set the map roomname to the roomname of the room. It's completely
redundant to set the roomname to an empty string and check if the
roomname of the room is empty.

desktop_version/src/Map.cpp

@@ -1677,10 +1677,7 @@ void mapclass::loadlevel(int rx, int ry)
 			}
 		}
 
-		roomname="";
-		if(room.roomname!=""){
-			roomname=room.roomname;
-		}
+		roomname = room.roomname;
 		extrarow = 1;
 		const int* tmap = ed.loadlevel(rx, ry);
 		SDL_memcpy(contents, tmap, sizeof(contents));