Silence java test app build

tests/Makefile

@@ -69,7 +69,7 @@ idempotent: idempotent_par
 delete_topics:
 	TESTS=none ./run-test.sh -D ./$(BIN) bare
 
-.PHONY: interceptor_test
+.PHONY:
 
 build: $(BIN) interceptor_test
 
@@ -80,9 +80,9 @@ test.o: ../src/librdkafka.a ../src-cpp/librdkafka++.a interceptor_test
 include ../mklove/Makefile.base
 
 ifeq ($(_UNAME_S),Darwin)
-interceptor_test:
+interceptor_test: .PHONY
 else
-interceptor_test:
+interceptor_test: .PHONY
 	$(MAKE) -C $@
 endif
 

tests/test.c

@@ -4016,7 +4016,7 @@ int test_run_java (const char *cls, const char **argv) {
         }
 
         /* Build */
-        r = system("make java");
+        r = system("make -s java");
 
         if (r == -1 || WIFSIGNALED(r) || WEXITSTATUS(r)) {
                 TEST_WARN("%s(%s): failed to build java class (code %d)\n",