treewide: convert PF_MEMALLOC manipulations to new helpers

treewide: convert PF_MEMALLOC manipulations to new helpers

We now have memalloc_noreclaim_{save,restore} helpers for robust setting
and clearing of PF_MEMALLOC.  Let's convert the code which was using the
generic tsk_restore_flags().  No functional change.

[[email protected]: in net/core/sock.c the hunk is missing]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Vlastimil Babka <[email protected]>
Acked-by: Michal Hocko <[email protected]>
Cc: Josef Bacik <[email protected]>
Cc: Lee Duncan <[email protected]>
Cc: Chris Leech <[email protected]>
Cc: "David S. Miller" <[email protected]>
Cc: Eric Dumazet <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Boris Brezillon <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Richard Weinberger <[email protected]>
Cc: Wouter Verhelst <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>