sched: Micro-optimize by dropping unnecessary task_rq() calls

We always know the rq used, let's just pass it around.
This seems to cut the size of scheduler core down a tiny bit:

Before:

  [linux]$ size kernel/sched/core.o.orig
     text    data     bss     dec     hex filename
    62760   16130    3876   82766   1434e kernel/sched/core.o.orig

After:

  [linux]$ size kernel/sched/core.o.patched
     text    data     bss     dec     hex filename
    62566   16130    3876   82572   1428c kernel/sched/core.o.patched

Probably speeds it up as well.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20130922142054.GA11499@redhat.com


Signed-off-by: Ingo Molnar <mingo@kernel.org>