msan also has a custom malloc that doesn't understand tcmalloc options

Change-Id: Ic6a718460e01d4727b4e74754f62a017a870a2ff
diff --git a/aos/realtime.cc b/aos/realtime.cc
index a0af97a..a41eb0d 100644
--- a/aos/realtime.cc
+++ b/aos/realtime.cc
@@ -74,7 +74,7 @@
   WriteCoreDumps();
   PCHECK(mlockall(MCL_CURRENT | MCL_FUTURE) == 0);
 
-#if !__has_feature(address_sanitizer)
+#if !__has_feature(address_sanitizer) && !__has_feature(memory_sanitizer)
   // Don't give freed memory back to the OS.
   CHECK_EQ(1, mallopt(M_TRIM_THRESHOLD, -1));
   // Don't use mmap for large malloc chunks.