svdsm: fix fuser import in supervdsmServer

Change-Id: I319a96e1357b5ed47ef5b6bcf3dec0ce678b9748
Signed-off-by: Federico Simoncelli <fsimonce@redhat.com>
Reviewed-on: http://gerrit.ovirt.org/13804
Reviewed-by: Yaniv Bronhaim <ybronhei@redhat.com>
Reviewed-by: Dan Kenigsberg <danken@redhat.com>