Fix duplicate symbol definition

src/engine/camera_interp_skip.c

@@ -1,6 +1,3 @@
-#ifndef CAMERA_INTERP_SKIP_C
-#define CAMERA_INTERP_SKIP_C
-
 #include "global.h"
 
 #define SQXYZ(vec) ((vec.x) * (vec.x) + (vec.y) * (vec.y) + (vec.z) * (vec.z))
@@ -109,5 +106,3 @@ bool should_interpolate_perspective(Vec3f* eye, Vec3f* at) {
 
     return true;
 }
-
-#endif

src/engine/fox_display.c

@@ -1,6 +1,5 @@
 #include "global.h"
 #include "mods/hit64.c"
-#include "camera_interp_skip.c"
 #include "assets/ast_arwing.h"
 #include "assets/ast_allies.h"
 #include "assets/ast_landmaster.h"