perf offcpu: Add missed btf_free

Caught by address/leak sanitizer.

Signed-off-by: Ian Rogers <irogers@google.com>
Cc: K Prateek Nayak <kprateek.nayak@amd.com>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: Sandipan Das <sandipan.das@amd.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: German Gomez <german.gomez@arm.com>
Cc: James Clark <james.clark@arm.com>
Cc: Nick Terrell <terrelln@fb.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Changbin Du <changbin.du@huawei.com>
Cc: liuwenyu <liuwenyu7@huawei.com>
Cc: Yang Jihong <yangjihong1@huawei.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Song Liu <song@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Cc: Yanteng Si <siyanteng@loongson.cn>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Link: https://lore.kernel.org/r/20231024222353.3024098-8-irogers@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>

Author: captain5050

tools/perf/util/bpf_off_cpu.c

@@ -98,29 +98,31 @@ static void off_cpu_finish(void *arg __maybe_unused)
 /* v5.18 kernel added prev_state arg, so it needs to check the signature */
 static void check_sched_switch_args(void)
 {
-	const struct btf *btf = btf__load_vmlinux_btf();
+	struct btf *btf = btf__load_vmlinux_btf();
 	const struct btf_type *t1, *t2, *t3;
 	u32 type_id;
 
 	type_id = btf__find_by_name_kind(btf, "btf_trace_sched_switch",
 					 BTF_KIND_TYPEDEF);
 	if ((s32)type_id < 0)
-		return;
+		goto cleanup;
 
 	t1 = btf__type_by_id(btf, type_id);
 	if (t1 == NULL)
-		return;
+		goto cleanup;
 
 	t2 = btf__type_by_id(btf, t1->type);
 	if (t2 == NULL || !btf_is_ptr(t2))
-		return;
+		goto cleanup;
 
 	t3 = btf__type_by_id(btf, t2->type);
 	/* btf_trace func proto has one more argument for the context */
 	if (t3 && btf_is_func_proto(t3) && btf_vlen(t3) == 5) {
 		/* new format: pass prev_state as 4th arg */
 		skel->rodata->has_prev_state = true;
 	}
+cleanup:
+	btf__free(btf);
 }
 
 int off_cpu_prepare(struct evlist *evlist, struct target *target,