Add simple stest smalloc tester

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
diff --git a/Makefile b/Makefile
index 40d47d5..3831ab8 100644
--- a/Makefile
+++ b/Makefile
@@ -80,6 +80,9 @@
 .c.o: .depend
 	$(QUIET_CC)$(CC) -o $@ -c $(CFLAGS) $(CPPFLAGS) $<
 
+t/stest: t/stest.o smalloc.o mutex.o
+	$(QUIET_CC)$(CC) $(LDFLAGS) $(CFLAGS) -o $@ t/stest.o smalloc.o mutex.o $(LIBS) $(LDFLAGS)
+
 fio: $(OBJS)
 	$(QUIET_CC)$(CC) $(LDFLAGS) $(CFLAGS) -o $@ $(OBJS) $(LIBS) $(LDFLAGS)