maple_tree: remove sanity check from mas_wr_slot_store()

After commit 5d659bbb ("maple_tree: introduce mas_wr_store_type()"),
the check here is redundant.

Let's remove it.

Link: https://lkml.kernel.org/r/20241017015809.23392-3-richard.weiyang@gmail.com


Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Reviewed-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>