UPSTREAM: fuse: ignore PG_workingset after stealing

Fix the "fuse: trying to steal weird page" warning.

Description from Johannes Weiner:

  "Think of it as similar to PG_active. It's just another usage/heat
   indicator of file and anon pages on the reclaim LRU that, unlike
   PG_active, persists across deactivation and even reclaim (we store it in
   the page cache / swapper cache tree until the page refaults).

   So if fuse accepts pages that can legally have PG_active set,
   PG_workingset is fine too."

Bug: 254441685
Reported-by: Thomas Lindroth <thomas.lindroth@gmail.com>
Fixes: 1899ad18c607 ("mm: workingset: tell cache transitions from workingset thrashing")
Cc: <stable@vger.kernel.org> # v4.20
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
(cherry picked from commit b89ecd60d38ec042d63bdb376c722a16f92bcb88)
Signed-off-by: Lee Jones <joneslee@google.com>
Change-Id: Ife78b93cf979bdb87756aaf570cb0935264b7e4d