Clean up internal libc logging.

We only need one logging API, and I prefer the one that does no
allocation and is thus safe to use in any context.

Also use O_CLOEXEC when opening the /dev/log files.

Move everything logging-related into one header file.

Change-Id: Ic1e3ea8e9b910dc29df351bff6c0aa4db26fbb58
diff --git a/libc/bionic/__stack_chk_fail.cpp b/libc/bionic/__stack_chk_fail.cpp
index cae66b1..d5031ac 100644
--- a/libc/bionic/__stack_chk_fail.cpp
+++ b/libc/bionic/__stack_chk_fail.cpp
@@ -29,8 +29,7 @@
 #include <stdlib.h>
 
 #include "bionic_ssp.h"
-#include "debug_format.h"
-#include "logd.h"
+#include "libc_logging.h"
 
 void __stack_chk_fail() {
   __libc_format_log(ANDROID_LOG_FATAL, "libc", "stack corruption detected");