vlr: drop unused is_ps parameter in vlr_subscr_req_lu()

the function vlr_subscr_req_lu() has a parameter is_ps, which is set
to vsub->vlr->cfg.is_ps by the only caller in vlr_lu_fsm.c. Inside the
function one can see that vsub->vlr->cfg.is_ps is used directly to
decide between PS or CS LU, we could also use is_ps there. Presumably
the parameter is_ps had been abandonned in an early development stage
and was not removed, so lets drop the parameter.

Change-Id: Id239721773b90099d122b232dae1ba457be9d255
3 files changed