brown-paper bug fix

Makefile.in

@@ -1111,8 +1111,9 @@ install_local: bin/why3doc
 .PHONY: bench test
 
 bench:: bin/why3.@OCAMLBEST@ bin/why3config.@OCAMLBEST@ plugins $(TOOLS)
-	test -f examples/use-api.ml && $(MAKE) test-api.@OCAMLBEST@
-	test -d examples/runstrat && $(MAKE) test-runstrat.@OCAMLBEST@
+	$(MAKE) test-api.@OCAMLBEST@
+	if test -d examples/runstrat ; then \
+	  $(MAKE) test-runstrat.@OCAMLBEST@ ; fi
 	sh bench/bench "bin/why3.@OCAMLBEST@"
 	@if test "@enable_coq_tactic@" = "yes"; then \
 	   echo "=== checking the Coq tactic ==="; \