perf stat: Update per-thread shadow stats

perf stat: Update per-thread shadow stats

The functions perf_stat__update_shadow_stats() is called to update the
shadow stats on a set of static variables.

But the static variables are the limitations to be extended to support
per-thread shadow stats.

This patch lets the perf_stat__update_shadow_stats() support to update
the shadow stats on a input parameter 'st' and uses
update_runtime_stat() to update the stats. It will not directly update
the static variables as before.

Signed-off-by: Jin Yao <[email protected]>
Acked-by: Jiri Olsa <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Kan Liang <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
[ Rename 'stat' variables to 'st' to build on centos:{5,6} and others where it shadows a global declaration ]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>