tools/testing/radix-tree: test maple tree chaining mas_preallocate() calls

tools/testing/radix-tree: test maple tree chaining mas_preallocate() calls

Testing calling multiple mas_preallocate() calls in a row after adjusting
the maple state.  Ensures new calls to mas_preallocate() will change the
number of allocated nodes.

Link: https://lkml.kernel.org/r/20250616184521.3382795-4-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Acked-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Hailong Liu <hailong.liu@oppo.com>
Cc: "Liam R. Howlett" <howlett@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Peng Zhang <zhangpeng.00@bytedance.com>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>