perf tools: Cleanup build directory before each test

Cleanup the fixdep tool before every test.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1480884178-8072-8-git-send-email-jolsa@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/tests/make

@@ -280,7 +280,7 @@ endif
 
 MAKEFLAGS := --no-print-directory
 
-clean := @(cd $(PERF); $(MAKE_F) -s $(O_OPT) clean >/dev/null)
+clean := @(cd $(PERF); $(MAKE_F) -s $(O_OPT) clean >/dev/null && $(MAKE) -s $(O_OPT) -C ../build clean >/dev/null)
 
 $(run):
 	$(call clean)