bring back r1.131:
authordlg <dlg@openbsd.org>
Mon, 11 Aug 2014 12:37:36 +0000 (12:37 +0000)
committerdlg <dlg@openbsd.org>
Mon, 11 Aug 2014 12:37:36 +0000 (12:37 +0000)
commit7ca6a9a248f60891bc51b5d702eae10f3ebd398c
treebf4f2e0d0bcf8db465036587dc41c783c5a0cbb8
parente878bfdfef0bd4c3fe7c129febf646283cdc261b
bring back r1.131:

take the pools mutex when copying stats out of it in the sysctl
path so we are guaranteed a consistent snapshot.
sys/kern/subr_pool.c