Update bionic kernel headers using update_all.py

Change-Id: I9c377436e9bf158e7236b3b7dcebf3e79fa961de
diff --git a/libc/kernel/common/linux/circ_buf.h b/libc/kernel/common/linux/circ_buf.h
index 438250c..262e163 100644
--- a/libc/kernel/common/linux/circ_buf.h
+++ b/libc/kernel/common/linux/circ_buf.h
@@ -7,23 +7,27 @@
  ***   structures, and macros generated from the original header, and thus,
  ***   contains no copyrightable information.
  ***
+ ***   To edit the content of this header, modify the corresponding
+ ***   source file (e.g. under external/kernel-headers/original/) then
+ ***   run bionic/libc/kernel/tools/update_all.py
+ ***
+ ***   Any manual change here will be lost the next time this script will
+ ***   be run. You've been warned!
+ ***
  ****************************************************************************
  ****************************************************************************/
 #ifndef _LINUX_CIRC_BUF_H
 #define _LINUX_CIRC_BUF_H 1
-
 struct circ_buf {
  char *buf;
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
  int head;
  int tail;
 };
-
 #define CIRC_CNT(head,tail,size) (((head) - (tail)) & ((size)-1))
-
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #define CIRC_SPACE(head,tail,size) CIRC_CNT((tail),((head)+1),(size))
-
 #define CIRC_CNT_TO_END(head,tail,size)   ({int end = (size) - (tail);   int n = ((head) + end) & ((size)-1);   n < end ? n : end;})
-
 #define CIRC_SPACE_TO_END(head,tail,size)   ({int end = (size) - 1 - (head);   int n = (end + (tail)) & ((size)-1);   n <= end ? n : end+1;})
-
 #endif
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */