perf tools: Move libbpf init in libbpf_init function

Move the libbpf init code into a single function, so that we have a single
place doing that.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Yonghong Song <yhs@fb.com>
Cc: bpf@vger.kernel.org
Cc: netdev@vger.kernel.org
Link: https://lore.kernel.org/r/20220422100025.1469207-4-jolsa@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/bpf-loader.c

@@ -99,16 +99,26 @@ static int bpf_perf_object__add(struct bpf_object *obj)
 	return perf_obj ? 0 : -ENOMEM;
 }
 
+static int libbpf_init(void)
+{
+	if (libbpf_initialized)
+		return 0;
+
+	libbpf_set_print(libbpf_perf_print);
+	libbpf_initialized = true;
+	return 0;
+}
+
 struct bpf_object *
 bpf__prepare_load_buffer(void *obj_buf, size_t obj_buf_sz, const char *name)
 {
 	LIBBPF_OPTS(bpf_object_open_opts, opts, .object_name = name);
 	struct bpf_object *obj;
+	int err;
 
-	if (!libbpf_initialized) {
-		libbpf_set_print(libbpf_perf_print);
-		libbpf_initialized = true;
-	}
+	err = libbpf_init();
+	if (err)
+		return ERR_PTR(err);
 
 	obj = bpf_object__open_mem(obj_buf, obj_buf_sz, &opts);
 	if (IS_ERR_OR_NULL(obj)) {
@@ -135,14 +145,13 @@ struct bpf_object *bpf__prepare_load(const char *filename, bool source)
 {
 	LIBBPF_OPTS(bpf_object_open_opts, opts, .object_name = filename);
 	struct bpf_object *obj;
+	int err;
 
-	if (!libbpf_initialized) {
-		libbpf_set_print(libbpf_perf_print);
-		libbpf_initialized = true;
-	}
+	err = libbpf_init();
+	if (err)
+		return ERR_PTR(err);
 
 	if (source) {
-		int err;
 		void *obj_buf;
 		size_t obj_buf_sz;