Sync SDL3 wiki -> header

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include/SDL3/SDL_render.h

@@ -1273,8 +1273,8 @@ extern SDL_DECLSPEC bool SDLCALL SDL_LockTexture(SDL_Texture *texture,
  *                `SDL_TEXTUREACCESS_STREAMING`.
  * \param rect a pointer to the rectangle to lock for access. If the rect is
  *             NULL, the entire texture will be locked.
- * \param surface this is filled in with an SDL surface representing the
- *                locked area.
+ * \param surface a pointer to an SDL surface of size **rect**. Don't assume
+ *                any specific pixel content.
  * \returns true on success or false on failure; call SDL_GetError() for more
  *          information.
  *