Undo most of ZzZombo's changes

- "If it ain't broke, don't fix it."
- Some of the changes were downright wrong and some were pointless, so undo
  everything that doesn't look like an actual improvement.

src/p_setup.cpp

@@ -3042,14 +3042,13 @@ void P_LoadBlockMap (MapData * map)
 	blockmap = blockmaplump+4;
 }
 
-line_t**				linebuffer;
-
 //
 // P_GroupLines
 // Builds sector line lists and subsector sector numbers.
 // Finds block bounding boxes for sectors.
-// [RH] Handles extra lights.
+// [RH] Handles extra lights
 //
+line_t**				linebuffer;
 
 static void P_GroupLines (bool buildmap)
 {