Update to v4.17.3 kernel headers.

Test: Builds, boots on a walleye.
Change-Id: I389d8b61ec00ea309e38d1b1a2e0dace48c21edb
diff --git a/libc/kernel/uapi/linux/const.h b/libc/kernel/uapi/linux/const.h
index 82b8bcd..6a4c1f7 100644
--- a/libc/kernel/uapi/linux/const.h
+++ b/libc/kernel/uapi/linux/const.h
@@ -16,8 +16,8 @@
  ***
  ****************************************************************************
  ****************************************************************************/
-#ifndef _LINUX_CONST_H
-#define _LINUX_CONST_H
+#ifndef _UAPI_LINUX_CONST_H
+#define _UAPI_LINUX_CONST_H
 #ifdef __ASSEMBLY__
 #define _AC(X,Y) X
 #define _AT(T,X) X
@@ -26,6 +26,8 @@
 #define _AC(X,Y) __AC(X, Y)
 #define _AT(T,X) ((T) (X))
 #endif
-#define _BITUL(x) (_AC(1, UL) << (x))
-#define _BITULL(x) (_AC(1, ULL) << (x))
+#define _UL(x) (_AC(x, UL))
+#define _ULL(x) (_AC(x, ULL))
+#define _BITUL(x) (_UL(1) << (x))
+#define _BITULL(x) (_ULL(1) << (x))
 #endif