Remove corking from AOS_LOG

Nobody has used it, and we are pushing more things towards glog or
flatbuffers.

Change-Id: Idbbbc5d85987e0d643d4c61958b5ffd81db0eb42
diff --git a/aos/logging/context.cc b/aos/logging/context.cc
index c6f1063..446e0df 100644
--- a/aos/logging/context.cc
+++ b/aos/logging/context.cc
@@ -73,9 +73,7 @@
 
 }  // namespace
 
-Context::Context() : implementation(GetImplementation()), sequence(0) {
-  cork_data.Reset();
-}
+Context::Context() : implementation(GetImplementation()), sequence(0) {}
 
 // Used in aos/linux_code/init.cc when a thread's name is changed.
 void ReloadThreadName() {