perf stat: Fix shadow declaration of close

Vinson reported shadow declaration of close introduced
by the following commit:

  106a94a0 perf stat: Introduce read_counters function

Using close_counters name instead.

Reported-by: Vinson Lee <vlee@twopensource.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Fixes: 106a94a0 ("perf stat: Introduce read_counters function")
Link: http://lkml.kernel.org/r/20150708111731.GA3512@krava.redhat.com


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