Revert "Update bionic kernel headers using update_all.py"

This reverts commit 94a85f663694e1869acb1c2e8a3c374a6fa3ab86

There is a smoke test failure for Prime but Crespo/Stingray are fine. Will revert the change for now until further investigation is made.
diff --git a/libc/kernel/common/linux/mempool.h b/libc/kernel/common/linux/mempool.h
index 50dbad2..fa2432b 100644
--- a/libc/kernel/common/linux/mempool.h
+++ b/libc/kernel/common/linux/mempool.h
@@ -7,33 +7,28 @@
  ***   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_MEMPOOL_H
 #define _LINUX_MEMPOOL_H
+
 #include <linux/wait.h>
+
 struct kmem_cache;
-/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
+
 typedef void * (mempool_alloc_t)(gfp_t gfp_mask, void *pool_data);
 typedef void (mempool_free_t)(void *element, void *pool_data);
+
 typedef struct mempool_s {
  spinlock_t lock;
-/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
  int min_nr;
  int curr_nr;
  void **elements;
+
  void *pool_data;
-/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
  mempool_alloc_t *alloc;
  mempool_free_t *free;
  wait_queue_head_t wait;
 } mempool_t;
-/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
+
 #endif