perf python: Fix up the build on architectures without HAVE_KVM_STAT_SUPPORT

Noticed while building on a raspbian arm 32-bit system.

There was also this other case, fixed by adding a missing util/stat.h
with the prototypes:

  /tmp/tmp.MbiSHoF3dj/perf-6.12.0-rc3/tools/perf/util/python.c:1396:6: error: no previous prototype for ‘perf_stat__set_no_csv_summary’ [-Werror=missing-prototypes]
   1396 | void perf_stat__set_no_csv_summary(int set __maybe_unused)
        |      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  /tmp/tmp.MbiSHoF3dj/perf-6.12.0-rc3/tools/perf/util/python.c:1400:6: error: no previous prototype for ‘perf_stat__set_big_num’ [-Werror=missing-prototypes]
   1400 | void perf_stat__set_big_num(int set __maybe_unused)
        |      ^~~~~~~~~~~~~~~~~~~~~~
  cc1: all warnings being treated as errors

In other architectures this must be building due to some lucky indirect
inclusion of that header.

Fixes: 9dabf40 ("perf python: Switch module to linking libraries from building source")
Reviewed-by: Ian Rogers <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Kan Liang <[email protected]>
Cc: Namhyung Kim <[email protected]>
Link: https://lore.kernel.org/lkml/ZxllAtpmEw5fg9oy@x1
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

Author: acmel

tools/perf/util/python.c

@@ -19,6 +19,7 @@
 #include "util/bpf-filter.h"
 #include "util/env.h"
 #include "util/kvm-stat.h"
+#include "util/stat.h"
 #include "util/kwork.h"
 #include "util/sample.h"
 #include "util/lock-contention.h"
@@ -1355,6 +1356,7 @@ PyMODINIT_FUNC PyInit_perf(void)
 
 unsigned int scripting_max_stack = PERF_MAX_STACK_DEPTH;
 
+#ifdef HAVE_KVM_STAT_SUPPORT
 bool kvm_entry_event(struct evsel *evsel __maybe_unused)
 {
 	return false;
@@ -1384,6 +1386,7 @@ void exit_event_decode_key(struct perf_kvm_stat *kvm __maybe_unused,
 			   char *decode __maybe_unused)
 {
 }
+#endif // HAVE_KVM_STAT_SUPPORT
 
 int find_scripts(char **scripts_array  __maybe_unused, char **scripts_path_array  __maybe_unused,
 		int num  __maybe_unused, int pathlen __maybe_unused)