tools/perf/build: Clean up various testcases

Prepare to include them into test-all.c directly, by making sure
that they build cleanly and without warnings.

Also make sure they make a certain amount of sense and don't crash
when executed.

Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/n/tip-Mn9gsdutzopoowk3xurqpsxE@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/tools/perf/config/feature-checks/test-libbfd.c b/tools/perf/config/feature-checks/test-libbfd.c
index d03339c..1886c78 100644
--- a/tools/perf/config/feature-checks/test-libbfd.c
+++ b/tools/perf/config/feature-checks/test-libbfd.c
@@ -1,7 +1,16 @@
 #include <bfd.h>
 
+extern int printf(const char *format, ...);
+
 int main(void)
 {
-	bfd_demangle(0, 0, 0);
+	char symbol[4096] = "FieldName__9ClassNameFd";
+	char *tmp;
+
+	tmp = bfd_demangle(0, symbol, 0);
+
+	printf("demangled symbol: {%s}\n", tmp);
+
 	return 0;
 }
+