removed useless pice of code from report host interface

This piece of code is useless since its functionalities are moved in the
rocks sync host vlan.

Vlan interfaces now are not managed anymore by the report command but they
are brought up dynamically when we start VM using rocks sync host vlan.

Jim Hayes reported that when you have a ipmi interface on a subnet ( e.g.
admin) and another interface tagged with a vlan on the same subnet (e.g.
admin) the rocks report host create an interface called ipmi.vlanid.

Signed-off-by: Luca Clementi <luca.clementi@gmail.com>
Cosmetic change to make code more readable

This does not change internal functionalities simply makes the code more
readable.

if device.startswith('vlan') is stating more clearly that device named
"vlan*" are not mangaed anymore in redhat network ifcfg scripts

Signed-off-by: Luca Clementi <luca.clementi@gmail.com>