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/item_use.c

@@ -509,7 +509,7 @@ static void SetDistanceOfClosestHiddenItem(u8 taskId, s16 itemDistanceX, s16 ite
         }
         else
         {
-            if (oldItemAbsX + oldItemAbsY == newItemAbsX + newItemAbsY 
+            if (oldItemAbsX + oldItemAbsY == newItemAbsX + newItemAbsY
             && (oldItemAbsY > newItemAbsY || (oldItemAbsY == newItemAbsY && tItemDistanceY < itemDistanceY)))
             {
                 // If items are equal distance, use whichever is closer on the Y axis or further south