specfile: Add dosfstools and psmisc as build required dep

Running a new F20 minimal install I installed all build reqs and saw
that the 'make rpm' step failed due to missing psmisc's fuser and
dosfstools mkfs.msdos.

Change-Id: Ib9091296608ce147d6b0b11de6cb888a3c3f9639
Signed-off-by: Antoni S. Puimedon <asegurap@redhat.com>
Reviewed-on: http://gerrit.ovirt.org/22114
Reviewed-by: Dan Kenigsberg <danken@redhat.com>