Actually manage memory in the old-style AOS logging

LeakSanitizer should be happy with it now. It's also still just as
thread-safe.

Change-Id: Id09a0349657cf4f719267b053f0ea3d8ec366256
diff --git a/frc971/wpilib/BUILD b/frc971/wpilib/BUILD
index 8010edc..1256d7f 100644
--- a/frc971/wpilib/BUILD
+++ b/frc971/wpilib/BUILD
@@ -370,6 +370,7 @@
         "//aos:init",
         "//aos/events:event_loop",
         "//aos/events:shm_event_loop",
+        "//aos/logging",
         "//aos/stl_mutex",
         "//aos/time",
         "//aos/util:phased_loop",