f2fs: remove unneeded f2fs_make_empty declaration

Remove f2fs_make_empty() declaration, since the main body of this function
is move into do_make_empty_dir() and the function is obsolete now.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/f2fs.h

@@ -1557,7 +1557,6 @@ int __f2fs_add_link(struct inode *, const struct qstr *, struct inode *, nid_t,
 void f2fs_delete_entry(struct f2fs_dir_entry *, struct page *, struct inode *,
 							struct inode *);
 int f2fs_do_tmpfile(struct inode *, struct inode *);
-int f2fs_make_empty(struct inode *, struct inode *);
 bool f2fs_empty_dir(struct inode *);
 
 static inline int f2fs_add_link(struct dentry *dentry, struct inode *inode)