pull in standard linux/kernel.h directly

We only need to overlay a few of our own types, so pull in the
standard linux/kernel.h and overlay our stuff on top of it.

BUG=chromium:878440
TEST=build works

Change-Id: I9bf3750778f7a88900a07a5b42281f316e7f162a
Reviewed-on: https://chromium-review.googlesource.com/1194720
Commit-Ready: Mike Frysinger <vapier@chromium.org>
Tested-by: Mike Frysinger <vapier@chromium.org>
Reviewed-by: Jorge Lucangeli Obes <jorgelo@chromium.org>
diff --git a/dm-bht.c b/dm-bht.c
index d77a465..c2f61cb 100644
--- a/dm-bht.c
+++ b/dm-bht.c
@@ -7,6 +7,7 @@
  * This file is released under the GPL.
  */
 
+#include <limits.h>
 #include <string.h>
 
 #include <asm/page.h>
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index ca0893d..f21a941 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -7,9 +7,8 @@
  */
 #ifndef VERITY_INCLUDE_LINUX_KERNEL_H_
 #define VERITY_INCLUDE_LINUX_KERNEL_H_
-/* Pull in _MAX defines */
-#include <limits.h>
-#include <stdint.h>
+
+#include_next <linux/kernel.h>
 
 #define ALIGN(x,a)		__ALIGN_MASK(x,(typeof(x))(a)-1)
 #define __ALIGN_MASK(x,mask)	(((x)+(mask))&~(mask))
@@ -17,13 +16,6 @@
 
 #define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
 
-#define sector_div(n, b) ({ \
-	int _res; \
-	_res = (n) % (b); \
-	(n) /= (b); \
-	_res; \
-})
-
 #define MIN(x, y) ({				\
 	typeof(x) _min1 = (x);			\
 	typeof(y) _min2 = (y);			\