liblog: remove visibility macros

Visibility is managed through version scripts now.

Bug: 123349183
Test: build
Change-Id: Ia388611a2ec14d0ff9c3896cfe97ccdce17dbb8b
diff --git a/liblog/logger.h b/liblog/logger.h
index b2479d2..1f632c0 100644
--- a/liblog/logger.h
+++ b/liblog/logger.h
@@ -156,10 +156,10 @@
 }
 #endif
 
-LIBLOG_HIDDEN void __android_log_lock();
-LIBLOG_HIDDEN int __android_log_trylock();
-LIBLOG_HIDDEN void __android_log_unlock();
+void __android_log_lock();
+int __android_log_trylock();
+void __android_log_unlock();
 
-extern LIBLOG_HIDDEN int __android_log_transport;
+extern int __android_log_transport;
 
 __END_DECLS