Call selinux_status_open() prior to use of selinux_status_updated().

The selinux_status_*() interfaces require calling selinux_status_open()
first.  Since this was not being called by servicemanager, the
selinux_status_updated() call was always failing and servicemanager
was not reloading service_contexts upon a policy reload.

Change-Id: I6ac62e114bbca99c5f0999feb918fcde15009274
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>