Revert "UBUNTU: SAUCE: kernfs: Do not match superblock in another user namespace when mounting"

BugLink: http://bugs.launchpad.net/bugs/1588056



This reverts commit aadbec3a.

Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Acked-by: Tim Gardner <tim.gardner@canonical.com>
Acked-by: Brad Figg <brad.figg@canonical.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>