UBUNTU: SAUCE: (namespace) autofs4: Use real_cred for requestor's ids

BugLink: http://bugs.launchpad.net/bugs/1629204



autofs passes the uid and gid of the user requesting a mount to
userspace, taking them from current->cred. ca6fe334 "fs: Call
d_automount with the filesystems creds" causes a regression as
current->cred is now the credentials of real root during automount
and not the credentials of the user. Fix this by taking the ids
from current->real_cred instead.

Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Acked-by: Brad Figg <brad.figg@canonical.com>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Ondrej Kubik <ondrej.kubik@canonical.com>
(cherry picked from commit d8779ed50cd530256e5f6bf083c1bd95f83d23f5)
Signed-off-by: Shrirang Bagul <shrirang.bagul@canonical.com>