mm: remove free_area_cache

Since all architectures have been converted to use vm_unmapped_area(),
there is no remaining use for the free_area_cache.

Signed-off-by: Michel Lespinasse <[email protected]>
Acked-by: Rik van Riel <[email protected]>
Cc: "James E.J. Bottomley" <[email protected]>
Cc: "Luck, Tony" <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: David Howells <[email protected]>
Cc: Helge Deller <[email protected]>
Cc: Ivan Kokshaysky <[email protected]>
Cc: Matt Turner <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Richard Henderson <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
17 files changed