Per feedback from rhc, manually set the base_ptr member
of the opal_buffer_t variable to NULL prior to calling
OBJ_RELEASE. A similar feature of opal_dss.load also
exists so likewise reset the base_ptr to NULL prior to
invoking it.
Hopefully the opal_buffer_t struct does not change
frequently.
Minor cleanups to reduce output when pmix_base_verbose
mca paramater is set.