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/battle_anim_flying.c

@@ -661,7 +661,7 @@ static void AnimFallingFeather_Step(struct Sprite *sprite)
     {
         switch (data->unk2 / 64)
         {
-        case 0: 
+        case 0:
             if ((u8)data->unk0_1 == 1) //casts to u8 here are necessary for matching
             {
                 data->unk0_0d = 1;