Fixed warning C4028: formal parameter 1 different from declaration

src/events/SDL_pen.c

@@ -112,7 +112,7 @@ static int SDLCALL pen_header_compare(const void *lhs, const void *rhs)
     return l->id - r->id;
 }
 
-SDL_Pen *SDL_GetPenPtr(const Uint32 instance_id)
+SDL_Pen *SDL_GetPenPtr(Uint32 instance_id)
 {
     unsigned int i;
 
@@ -271,7 +271,7 @@ static void pen_sort(void)
     pen_handler.sorted = SDL_TRUE;
 }
 
-SDL_Pen *SDL_PenModifyBegin(const Uint32 instance_id)
+SDL_Pen *SDL_PenModifyBegin(Uint32 instance_id)
 {
     SDL_PenID id = { 0 };
     const size_t alloc_growth_constant = 1; /* Expect few pens */