knfs: add fsstress and kernel build

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Merge pull request #18 from ceph/wip-knfs-fsstress

knfs: add fsstress and kernel build
knfs: test v3 and v4

Signed-off-by: Sage Weil <sage@inktank.com>
upgrade/dumpling-x: more mon scrub whitelist

There are two log messages; whitelist them both

Signed-off-by: Sage Weil <sage@inktank.com>