The geteuid() addition is being made the first element of the lxc_list,
but the first element is just a head whose entry is ignored.  Therefore
userns_exec_1() was starting its tasks without the caller's uid mapped
into the namespace.
Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
Acked-by: Stéphane Graber <stgraber@ubuntu.com>