Put pointer to reseed pool in pool struct and automatically pull entropy from
it if it is set.  This lets us remove the EXTRACT_SECONDARY flag.
Signed-off-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>