vmscan: change shrinker API by passing shrink_control struct

vmscan: change shrinker API by passing shrink_control struct

Change each shrinker's API by consolidating the existing parameters into
shrink_control struct.  This will simplify any further features added w/o
touching each file of shrinker.

[[email protected]: fix build]
[[email protected]: fix warning]
[[email protected]: fix up new shrinker API]
[[email protected]: fix xfs warning]
[[email protected]: update gfs2]
Signed-off-by: Ying Han <[email protected]>
Cc: KOSAKI Motohiro <[email protected]>
Cc: Minchan Kim <[email protected]>
Acked-by: Pavel Emelyanov <[email protected]>
Cc: KAMEZAWA Hiroyuki <[email protected]>
Cc: Mel Gorman <[email protected]>
Acked-by: Rik van Riel <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Hugh Dickins <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Steven Whitehouse <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>