PRTL_SPLAY_LINKS
RtlSubtreeSuccessor(
  IN  PRTL_SPLAY_LINKS Links
  );

Routine Description:

    The SubtreeSuccessor function takes as input a pointer to a splay link
    in a tree and returns a pointer to the successor of the input node of
    the substree rooted at the input node.  If there is not a successor, the
    return value is NULL.

Arguments:

    Links - Supplies a pointer to a splay link in a tree.

Return Value:

    PRTL_SPLAY_LINKS - returns a pointer to the successor in the subtree