Fix documentation for SDL_sinf

include/SDL3/SDL_stdinc.h

@@ -5577,7 +5577,7 @@ extern SDL_DECLSPEC double SDLCALL SDL_sin(double x);
  * Range: `-1 <= y <= 1`
  *
  * This function operates on single-precision floating point values, use
- * SDL_sinf for double-precision floats.
+ * SDL_sin for double-precision floats.
  *
  * This function may use a different approximation across different versions,
  * platforms and configurations. i.e, it can return a different value given