mm/huge_memory: move filemap management into the file split helper

Reviewed-by: Yeoreum Yun yeoreum.yun@arm.com On Tue, Sep 15, 2026 at 01:14:52AM +0800, Kairui Song via B4 Relay wrote: > From: Kairui Song kasong@tencent.com > > Only file split needs the filema