mm/memory-failure: give up error handling for non-tail-refcounted thp

mm/memory-failure: give up error handling for non-tail-refcounted thp

"non anonymous thp" case is still racy with freeing thp, which causes
panic due to put_page() for refcount-0 page.  It seems that closing up
this race might be hard (and/or not worth doing,) so let's give up the
error handling for this case.

Signed-off-by: Naoya Horiguchi <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Dean Nelson <[email protected]>
Cc: Tony Luck <[email protected]>
Cc: "Kirill A. Shutemov" <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: David Rientjes <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>