d2256fb parallels_driver: Utilize parallelsDomObjFromDomain()

Authored and Committed by mprivozn 9 years ago
    parallels_driver: Utilize parallelsDomObjFromDomain()
    
    Instead of each API copying the same lines of code, lets use the
    generic function designed just for that purpose. At the same time,
    drop useless connection object locking in some functions.
    
    Signed-off-by: Michal Privoznik <mprivozn@redhat.com>