core: Fix host deploy logs path displayed in Events tab

Fixes host deploy logs path displayed in Events tab in case of
unsuccessfull deployment of host.

Change-Id: Ifcba8acd649bb97dc793a2f82062f9bc71a36720
Bug-Url: https://bugzilla.redhat.com/1155603
Signed-off-by: Martin Perina <mperina@redhat.com>