If we created a new node to replace an entry which had search marks set,
we were setting the search mark on every entry in that node.  That works
fine when we're splitting to order 0, but when splitting to a larger
order, we must not set the search marks on the sibling entries.

Link: https://lkml.kernel.org/r/20240501153120.4094530-1-willy@infradead.org
Fixes: c010d47f ("mm: thp: split huge page to any lower order pages")
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reported-by: Luis Chamberlain <mcgrof@kernel.org>
Link: https://lore.kernel.org/r/ZjFGCOYk3FK_zVy3@bombadil.infradead.orgTested-by: Luis Chamberlain <mcgrof@kernel.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>