perf stat: Move 'initial_delay' to 'struct perf_stat_config'

Move the static 'initial_delay' variable to 'struct perf_stat_config',
so it can be passed around and used outside the 'perf stat' command.

Add 'struct perf_stat_config' argument to create_perf_stat_counter() and
use its 'initial_delay' member instead of the static one.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20180830063252.23729-3-jolsa@kernel.org


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>