staging/lustre/ptlrpc: remove sptlrpc_conf_target_get_rules()

Remove the unused function sptlrpc_conf_target_get_rules() and its
supporting functions.

Signed-off-by: John L. Hammond <john.hammond@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>