Removed trailing spaces in the most relevant files

Command used for the job:
egrep -rl ' $' --include *.c --include *.h --include  *.s --include  *.inc --include  *.txt *  | xargs sed -i 's/\s\+$//g'

Credits to Grant Murphy from Stack Overflow.

src/overworld.c

@@ -823,7 +823,7 @@ void LoadMapFromCameraTransition(u8 mapGroup, u8 mapNum)
     ResetFieldTasksArgs();
     RunOnResumeMapScript();
 
-    if (gMapHeader.regionMapSectionId != MAPSEC_BATTLE_FRONTIER 
+    if (gMapHeader.regionMapSectionId != MAPSEC_BATTLE_FRONTIER
      || gMapHeader.regionMapSectionId != sLastMapSectionId)
         ShowMapNamePopup();
 }
@@ -2235,10 +2235,10 @@ static void CB1_UpdateLinkState(void)
 
         // Note: Because guestId is between 0 and 4, while the smallest key code is
         // LINK_KEY_CODE_EMPTY, this is functionally equivalent to `sPlayerKeyInterceptCallback(0)`.
-        // It is expecting the callback to be KeyInterCB_SelfIdle, and that will 
+        // It is expecting the callback to be KeyInterCB_SelfIdle, and that will
         // completely ignore any input parameters.
         //
-        // UpdateHeldKeyCode performs a sanity check on its input; if 
+        // UpdateHeldKeyCode performs a sanity check on its input; if
         // sPlayerKeyInterceptCallback echoes back the argument, which is selfId, then
         // it'll use LINK_KEY_CODE_EMPTY instead.
         //
@@ -3051,7 +3051,7 @@ static void SetPlayerFacingDirection(u8 linkPlayerId, u8 facing)
             #define TEMP gLinkPlayerMovementModes[linkPlayerObjEvent->movementMode](linkPlayerObjEvent, objEvent, facing)
 
             gMovementStatusHandler[TEMP](linkPlayerObjEvent, objEvent);
-            
+
             // Clean up the hack.
             #undef TEMP
         }