stdinc: Docs said "macro" but meant "datatype."

include/SDL3/SDL_stdinc.h

@@ -492,7 +492,7 @@ typedef uint64_t Uint64;
  * and SDL_SECONDS_TO_NS(), and between Windows FILETIME values with
  * SDL_TimeToWindows() and SDL_TimeFromWindows().
  *
- * \since This macro is available since SDL 3.2.0.
+ * \since This datatype is available since SDL 3.2.0.
  *
  * \sa SDL_MAX_SINT64
  * \sa SDL_MIN_SINT64