Recently we made perf_evsel__init call hists__init, which broke the perf
python binding:
[root@emilia linux]# ./tools/perf/python/twatch.py
Traceback (most recent call last):
  File "./tools/perf/python/twatch.py", line 16, in <module>
    import perf
ImportError: /home/acme/git/build/perf/python/perf.so: undefined symbol: hists__init
Fix it by moving the hists__init function to its only caller, evsel.c.
This way we avoid dragging in other parts of tools/perf/util/ to the
perf python binding.
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-5nffmdt5mu6ozxgj54oi4qon@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
        return size;
 }
 
+static void hists__init(struct hists *hists)
+{
+       memset(hists, 0, sizeof(*hists));
+       hists->entries_in_array[0] = hists->entries_in_array[1] = RB_ROOT;
+       hists->entries_in = &hists->entries_in_array[0];
+       hists->entries_collapsed = RB_ROOT;
+       hists->entries = RB_ROOT;
+       pthread_mutex_init(&hists->lock, NULL);
+}
+
 void perf_evsel__init(struct perf_evsel *evsel,
                      struct perf_event_attr *attr, int idx)
 {
 
 
        return ret;
 }
-
-void hists__init(struct hists *hists)
-{
-       memset(hists, 0, sizeof(*hists));
-       hists->entries_in_array[0] = hists->entries_in_array[1] = RB_ROOT;
-       hists->entries_in = &hists->entries_in_array[0];
-       hists->entries_collapsed = RB_ROOT;
-       hists->entries = RB_ROOT;
-       pthread_mutex_init(&hists->lock, NULL);
-}
 
        struct callchain_cursor callchain_cursor;
 };
 
-void hists__init(struct hists *hists);
-
 struct hist_entry *__hists__add_entry(struct hists *self,
                                      struct addr_location *al,
                                      struct symbol *parent, u64 period);