mm: vmscan: remove shrink_control arg from do_try_to_free_pages()

mm: vmscan: remove shrink_control arg from do_try_to_free_pages()

There is no need passing on a shrink_control struct from
try_to_free_pages() and friends to do_try_to_free_pages() and then to
shrink_zones(), because it is only used in shrink_zones() and the only
field initialized on the top level is gfp_mask, which is always equal to
scan_control.gfp_mask.  So let's move shrink_control initialization to
shrink_zones().

Signed-off-by: Vladimir Davydov <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: Dave Chinner <[email protected]>
Cc: Glauber Costa <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>