perf tests: Add missing counts.h

Those are getting counts.h via evsel.h, that don't strictly need
counts.h, just forward declarations for some structs, so add it here
before we remove it from there.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-phldqlfxxu563txja7evd4zt@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/tests/openat-syscall-all-cpus.c

@@ -16,6 +16,7 @@
 #include "cpumap.h"
 #include "debug.h"
 #include "stat.h"
+#include "util/counts.h"
 
 int test__openat_syscall_event_on_all_cpus(struct test *test __maybe_unused, int subtest __maybe_unused)
 {

tools/perf/tests/openat-syscall.c

@@ -10,6 +10,7 @@
 #include "evsel.h"
 #include "debug.h"
 #include "tests.h"
+#include "util/counts.h"
 
 int test__openat_syscall_event(struct test *test __maybe_unused, int subtest __maybe_unused)
 {