maple_tree: fix freeing of nodes in rcu mode

maple_tree: fix freeing of nodes in rcu mode

The walk to destroy the nodes was not always setting the node type and
would result in a destroy method potentially using the values as nodes.
Avoid this by setting the correct node types.  This is necessary for the
RCU mode of the maple tree.

Link: https://lkml.kernel.org/r/20230227173632.3292573-4-surenb@google.com
Cc: <Stable@vger.kernel.org>
Fixes: 54a611b60590 ("Maple Tree: add new data structure")
Signed-off-by: Liam Howlett <Liam.Howlett@oracle.com>