XdbeDeallocateBackBufferName - frees a DBE buffer.
#include <X11/extensions/Xdbe.h>
Status XdbeDeallocateBackBufferName(
   Display *dpy,
   XdbeBackBuffer buffer)
This function frees a drawable ID, buffer, that was obtained via
  XdbeAllocateBackBufferName(). The buffer must be a valid name for the
  back buffer of a window, or a protocol error results.
  - BadBuffer
- The specified buffer is not associated with a window.
DBE, XdbeAllocateBackBufferName(), XdbeBeginIdiom(),
  XdbeEndIdiom(), XdbeFreeVisualInfo(),
  XdbeGetBackBufferAttributes(), XdbeGetVisualInfo(),
  XdbeQueryExtension(), XdbeSwapBuffers().