perf test: Add 'struct test *' to the test functions

This way we'll be able to pass more test specific parameters without
having to change this function signature.

Will be used by the upcoming 'shell tests', shell scripts that will
call perf tools and check if they work as expected, comparing its
effects on the system (think 'perf probe foo') the output produced, etc.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Thomas Richter <tmricht@linux.vnet.ibm.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-wq250w7j1opbzyiynozuajbl@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/tests/backward-ring-buffer.c b/tools/perf/tests/backward-ring-buffer.c
index 50f6d7a..d233ad3 100644
--- a/tools/perf/tests/backward-ring-buffer.c
+++ b/tools/perf/tests/backward-ring-buffer.c
@@ -75,7 +75,7 @@ static int do_test(struct perf_evlist *evlist, int mmap_pages,
 }
 
 
-int test__backward_ring_buffer(int subtest __maybe_unused)
+int test__backward_ring_buffer(struct test *test __maybe_unused, int subtest __maybe_unused)
 {
 	int ret = TEST_SKIP, err, sample_count = 0, comm_count = 0;
 	char pid[16], sbuf[STRERR_BUFSIZE];