Update kernel headers to v3.14.

Other changes:
- Modify update_all.py to skip ion header files when importing into aosp.
- Fix generate_uapi_headers.sh to handle imports from a linux-stable kernel.

Change-Id: I1ad81b9ccb063c21740f9875f2cc1238052cd4b3
diff --git a/libc/kernel/uapi/asm-generic/statfs.h b/libc/kernel/uapi/asm-generic/statfs.h
index 860e584..1c8c589 100644
--- a/libc/kernel/uapi/asm-generic/statfs.h
+++ b/libc/kernel/uapi/asm-generic/statfs.h
@@ -22,7 +22,7 @@
 #ifndef __statfs_word
 /* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #if __BITS_PER_LONG == 64
-#define __statfs_word long
+#define __statfs_word __kernel_long_t
 #else
 #define __statfs_word __u32
 /* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */