Clean up battle anim effects file

src/battle_anim_effects_3.c

@@ -2504,13 +2504,10 @@ void sub_815BE04(struct Sprite *sprite)
 
 static void sub_815BF44(struct Sprite *sprite)
 {
-    int var0;
-    s8 var1;
-
-    var0 = (u16)sprite->data[2] + (u16)sprite->data[3];
-    var1 = var0 >> 8;
-    sprite->pos2.y -= var1;
-    sprite->data[3] = var0 & 0xFF;
+    s16 delta = sprite->data[3] + sprite->data[2];
+    sprite->pos2.y -= delta >> 8;
+    sprite->data[3] += sprite->data[2];
+    sprite->data[3] &= 0xFF;
     if (sprite->data[4] == 0 && sprite->pos2.y < -8)
     {
         gSprites[sprite->data[6]].invisible = 0;
@@ -2543,19 +2540,12 @@ static void sub_815BFF4(struct Sprite *sprite)
 
 static void sub_815C050(struct Sprite *sprite)
 {
-    u16 d2;
-    register u16 d3 asm("r1");
-    int var0;
-    s8 var1;
-
     if (!sprite->invisible)
     {
-        d2 = sprite->data[2];
-        d3 = sprite->data[3];
-        var0 = d2 + d3;
-        var1 = var0 >> 8;
-        sprite->pos2.y -= var1;
-        sprite->data[3] = var0 & 0xFF;
+        s16 delta = sprite->data[3] + sprite->data[2];
+        sprite->pos2.y -= delta >> 8;
+        sprite->data[3] += sprite->data[2];
+        sprite->data[3] &= 0xFF;
         if (--sprite->data[1] == -1)
         {
             sprite->invisible = 1;