lxc.container.conf(5): update guidance for lxc.mount.entry mount target
lxc.container.conf(5): update guidance for lxc.mount.entry mount target

For years it has been best practice to use a relative path as
the mount target.  But the manpage hasn't reflect that.  Fix it.

Signed-off-by: Serge Hallyn <3df611b026e4639bee8aef7a4beb2e39fcebb313@ubuntu.com>
Acked-by: Dwight Engen <1793d65cf7b9eefb2bb8f5bee9a4b8ba782c26da@oracle.com>

ojkastl/lxc_Patches,ojkastl/lxc_Patches,ojkastl/lxc_Patches,ojkastl/lxc_Patches