Prefix STRINGIFY with AOS_ for uniqueness.

A third party library collided.

Change-Id: Iaebafb4f5afc6967ea5923b51d678af5acda07a1
diff --git a/aos/logging/printf_formats.h b/aos/logging/printf_formats.h
index a04f1f2..df97d6e 100644
--- a/aos/logging/printf_formats.h
+++ b/aos/logging/printf_formats.h
@@ -10,7 +10,7 @@
 // implementations.cc.
 
 #define AOS_TIME_FORMAT \
-  "%010" PRId32 ".%0" STRINGIFY(AOS_TIME_NSECONDS_DIGITS) PRId32 "s"
+  "%010" PRId32 ".%0" AOS_STRINGIFY(AOS_TIME_NSECONDS_DIGITS) PRId32 "s"
 #define AOS_TIME_ARGS(sec, nsec) sec, (nsec / AOS_TIME_NSECONDS_DENOMINATOR)
 
 #define AOS_LOGGING_BASE_FORMAT \