perf evsel: Do not use globals in config()

Instead receive a callchain_param pointer to configure callchain
aspects, not doing so if NULL is passed.

This will allow fine grained control over which evsels in an evlist
gets callchains enabled.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-2mupip6khc92mh5x4nw9to82@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/tests/bpf.c

@@ -138,7 +138,7 @@ static int do_test(struct bpf_object *obj, int (*func)(void),
 	perf_evlist__splice_list_tail(evlist, &parse_evlist.list);
 	evlist->nr_groups = parse_evlist.nr_groups;
 
-	perf_evlist__config(evlist, &opts);
+	perf_evlist__config(evlist, &opts, NULL);
 
 	err = perf_evlist__open(evlist);
 	if (err < 0) {