maple_tree: add some alloc node test case

Add some maple_tree alloc node tese case.

Link: https://lkml.kernel.org/r/20240626160631.3636515-2-Liam.Howlett@oracle.com


Signed-off-by: Jiazi Li <jqqlijiazi@gmail.com>
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Suggested-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>