Btrfs: make iref_to_path non static

Make iref_to_path non static (needed in send) and rename
it to btrfs_iref_to_path

Signed-off-by: Alexander Block <ablock84@googlemail.com>
diff --git a/fs/btrfs/backref.h b/fs/btrfs/backref.h
index c18d8ac..1a76579 100644
--- a/fs/btrfs/backref.h
+++ b/fs/btrfs/backref.h
@@ -21,6 +21,7 @@
 
 #include "ioctl.h"
 #include "ulist.h"
+#include "extent_io.h"
 
 #define BTRFS_BACKREF_SEARCH_COMMIT_ROOT ((struct btrfs_trans_handle *)0)
 
@@ -60,6 +61,9 @@
 				struct btrfs_fs_info *fs_info, u64 bytenr,
 				u64 delayed_ref_seq, u64 time_seq,
 				struct ulist **roots);
+char *btrfs_iref_to_path(struct btrfs_root *fs_root, struct btrfs_path *path,
+			 struct btrfs_inode_ref *iref, struct extent_buffer *eb,
+			 u64 parent, char *dest, u32 size);
 
 struct btrfs_data_container *init_data_container(u32 total_bytes);
 struct inode_fs_paths *init_ipath(s32 total_bytes, struct btrfs_root *fs_root,