Fix invocation of setup-vif-rules from set_locking_mode

Signed-off-by: Jon Ludlam <jonathan.ludlam@eu.citrix.com>
Udev jiggery-pokery

Add in the udev scripts from xen-api.git. Note these are only
installed in the xen-api-libs-specs specfile, not in the
xenserver-core specfile.

Signed-off-by: Jon Ludlam <jonathan.ludlam@eu.citrix.com>