sched: Fix calc_cfs_shares() to consider blocked_load_avg also

From: Namhyung Kim <namhyung.kim@lge.com>

The calc_tg_weight() and calc_cfs_shares() used cfs_rq->load.weight
but this is no longer valid for per-entity load tracking since
cfs_rq->tg_load_contrib consists of runnable_load_avg and blocked_
load_avg.  Simply using load.weight here will lose blocked_load_avg
part so will result in an inaccurate share.

Cc: Paul Turner <pjt@google.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>