LU-3024 test: use facet name in init_param_vars

When configuring jobstats init_parm_vars should call
set_conf_param_and_check with the facet name (client) rather then the
hostname.

Signed-off-by: John L. Hammond <john.hammond@intel.com>
Change-Id: I00b99ec3172d3e108fb6dd6d94825badf81e84df
Reviewed-on: http://review.whamcloud.com/5835
Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Niu Yawei <yawei.niu@intel.com>
Reviewed-by: Jian Yu <jian.yu@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>