[PATCH] btrfs: Fix compilation on big endian systems

["Pali Rohár" <pali@kernel.org>]

Fix following two compile errors on big endian systems:

  CC      fs/btrfs/btrfs.o
In file included from include/linux/byteorder/big_endian.h:107,
                 from ./arch/powerpc/include/asm/byteorder.h:82,
                 from ./arch/powerpc/include/asm/bitops.h:8,
                 from include/linux/bitops.h:152,
                 from include/uuid.h:9,
                 from fs/btrfs/btrfs.c:10:
fs/btrfs/conv-funcs.h: In function ‘btrfs_key_to_disk’:
include/linux/byteorder/generic.h:90:21: error: ‘__cpu_to_le16’ undeclared (first use in this function); did you mean ‘__cpu_to_le16p’?
 #define cpu_to_le16 __cpu_to_le16
                     ^~~~~~~~~~~~~
fs/btrfs/conv-funcs.h:79:10: note: in expansion of macro ‘cpu_to_le16’
   __u16: cpu_to_le16,     \
          ^~~~~~~~~~~

  CC      fs/btrfs/compression.o
In file included from ./arch/powerpc/include/asm/unaligned.h:9,
                 from fs/btrfs/compression.c:16:
include/linux/unaligned/access_ok.h:6:19: error: redefinition of ‘get_unaligned_le16’
 static inline u16 get_unaligned_le16(const void *p)
                   ^~~~~~~~~~~~~~~~~~
In file included from fs/btrfs/ctree.h:16,
                 from fs/btrfs/btrfs.h:12,
                 from fs/btrfs/compression.c:8:
include/linux/unaligned/le_byteshift.h:40:19: note: previous definition of ‘get_unaligned_le16’ was here
 static inline u16 get_unaligned_le16(const void *p)
                   ^~~~~~~~~~~~~~~~~~

Include file asm/unaligned.h contains arch specific macros and functions
for unaligned access as opposite to linux/unaligned le_byteshift.h which
contains macros and functions specific to little endian systems only.

Signed-off-by: Pali Rohár <pali@kernel.org>
---
 fs/btrfs/btrfs.h | 2 +-
 fs/btrfs/ctree.h | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/btrfs/btrfs.h b/fs/btrfs/btrfs.h
index 7d8b395b2646..a52587e0637a 100644
--- a/fs/btrfs/btrfs.h
+++ b/fs/btrfs/btrfs.h
@@ -9,7 +9,7 @@
 #define __BTRFS_BTRFS_H__
 
 #include <linux/rbtree.h>
-#include "conv-funcs.h"
+#include "ctree.h"
 
 extern struct btrfs_info btrfs_info;
 extern struct btrfs_fs_info *current_fs_info;
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 219c410b189f..55112318a330 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -13,7 +13,7 @@
 #include <compiler.h>
 #include <linux/rbtree.h>
 #include <linux/bug.h>
-#include <linux/unaligned/le_byteshift.h>
+#include <asm/unaligned.h>
 #include <u-boot/crc.h>
 #include "kernel-shared/btrfs_tree.h"
 #include "crypto/hash.h"
-- 
2.20.1