libperf: Move 'nr_mmaps' from 'struct evlist' to 'struct perf_evlist'

Moving 'nr_mmaps' from 'struct evlist' to 'struct perf_evlist', it will
be used in following patches.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lore.kernel.org/lkml/20190913132355.21634-21-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/tests/keep-tracking.c b/tools/perf/tests/keep-tracking.c
index c6030fd..bd4ae8e 100644
--- a/tools/perf/tests/keep-tracking.c
+++ b/tools/perf/tests/keep-tracking.c
@@ -36,7 +36,7 @@ static int find_comm(struct evlist *evlist, const char *comm)
 	int i, found;
 
 	found = 0;
-	for (i = 0; i < evlist->nr_mmaps; i++) {
+	for (i = 0; i < evlist->core.nr_mmaps; i++) {
 		md = &evlist->mmap[i];
 		if (perf_mmap__read_init(md) < 0)
 			continue;