packaging: setup: hostname: handle bond correctly

the interface name appearing at the address line does not include
the '@xxx'.

Bug-Url: https://bugzilla.redhat.com/show_bug.cgi?id=1004582
Change-Id: Ib334272c3a415b86b2425a459fe302ed23acf241
Signed-off-by: Alon Bar-Lev <alonbl@redhat.com>