perf tests: Skip the llvm and bpf tests if HAVE_LIBBPF_SUPPORT isn't defined

If either NO_LIBBPF=1 is passed, explicitely disabling it or if libbpf
is not available due to some missing dependency, skip its tests, telling
the user the feature isn't available.

  # perf test
  <SNIP>
  40: LLVM search and compile                                         : Skip (not compiled in)
  41: Session topology                                                : Ok
  42: BPF filter                                                      : Skip (not compiled in)
  <SNIP>

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/tests/llvm.c b/tools/perf/tests/llvm.c
index ae6cda8..98da8a8 100644
--- a/tools/perf/tests/llvm.c
+++ b/tools/perf/tests/llvm.c
@@ -2,13 +2,13 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#include <bpf/libbpf.h>
-#include <util/llvm-utils.h>
-#include "llvm.h"
 #include "tests.h"
 #include "debug.h"
 
 #ifdef HAVE_LIBBPF_SUPPORT
+#include <bpf/libbpf.h>
+#include <util/llvm-utils.h>
+#include "llvm.h"
 static int test__bpf_parsing(void *obj_buf, size_t obj_buf_sz)
 {
 	struct bpf_object *obj;
@@ -19,14 +19,6 @@ static int test__bpf_parsing(void *obj_buf, size_t obj_buf_sz)
 	bpf_object__close(obj);
 	return TEST_OK;
 }
-#else
-static int test__bpf_parsing(void *obj_buf __maybe_unused,
-			     size_t obj_buf_sz __maybe_unused)
-{
-	pr_debug("Skip bpf parsing\n");
-	return TEST_OK;
-}
-#endif
 
 static struct {
 	const char *source;
@@ -170,3 +162,19 @@ const char *test__llvm_subtest_get_desc(int subtest)
 
 	return bpf_source_table[subtest].desc;
 }
+#else //HAVE_LIBBPF_SUPPORT
+int test__llvm(struct test *test __maybe_unused, int subtest __maybe_unused)
+{
+	return TEST_SKIP;
+}
+
+int test__llvm_subtest_get_nr(void)
+{
+	return 0;
+}
+
+const char *test__llvm_subtest_get_desc(int subtest __maybe_unused)
+{
+	return NULL;
+}
+#endif // HAVE_LIBBPF_SUPPORT