Minor bugfix to wait_for_guest_boot.
Minor bugfix to wait_for_guest_boot.

Make sure to set addr to None before our try blocks, so
we make sure it is defined before trying to access it.

Signed-off-by: Chris Lalancette <60b62644009db6b194cc0445b64e9b27bb26433a@redhat.com>

mgagne/oz,cernops/oz,mgagne/oz,cernops/oz,NeilBryant/oz,nullr0ute/oz,imcleod/oz,clalancette/oz,ndonegan/oz,nullr0ute/oz,NeilBryant/oz,imcleod/oz,moofrank/oz,moofrank/oz,ndonegan/oz,clalancette/oz