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/union_room_battle.c

@@ -166,7 +166,7 @@ void CB2_UnionRoomBattle(void)
     case 4:
         if (GetBlockReceivedStatus() == 3)
         {
-            if (gBlockRecvBuffer[0][0] == (ACTIVITY_ACCEPT | IN_UNION_ROOM) 
+            if (gBlockRecvBuffer[0][0] == (ACTIVITY_ACCEPT | IN_UNION_ROOM)
              && gBlockRecvBuffer[1][0] == (ACTIVITY_ACCEPT | IN_UNION_ROOM))
             {
                 BeginNormalPaletteFade(PALETTES_ALL, 0, 0, 16, RGB_BLACK);