To be applied in MASTER branch.

This patch is a complement of commit 5e9dd516e2e0 ("add bonding &
xDSL to the list of devices brought up afterwards (#97030,#91399)"),
ensuring that GRE and IPIP tunnels are brought up after base
interfaces are up, and bring down before the underlying interface
goes down.

ALSO

A "# service network stop" tries to stop already stopped or non-existent
interfaces when a 'tunnel' interface is present.
The function check_device_down will use tunnel0 as a reference interface
(when it is up) and the network script will try to stop every interface
existent in /etc/sysconfig/network-scripts/ifcfg-*, regardless if it actually
exists or is up.

This patch fixes the variable and check_device_down now checks the correct
interface and down/skip the interfaces accordingly.

Signed-off-by: Rodrigo Freire <rfreire@redhat.com>
 
--- Rodrigo A B Freire .--. - ..--- .-. --- -..