Refactoring reportError func

Extracting the error function from inner function to class level function.

Change-Id: I041a662f4fe02f671a7335d7eca84704443f5bee
Signed-off-by: Kobi Ianko <kianku@redhat.com>
Reviewed-on: http://gerrit.ovirt.org/28482
Reviewed-by: Francesco Romani <fromani@redhat.com>
Reviewed-by: Dan Kenigsberg <danken@redhat.com>
Tested-by: Kobi Ianko <kobi@redhat.com>