libext2fs: Provide prototype for ext2fs_symlink()

New function ext2fs_symlink() doesn't have a prototype in ext2fs.h and
thus debugfs compilation gives warning:

debugfs.c:2219:2: warning: implicit declaration of function 'ext2fs_symlink'

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
diff --git a/lib/ext2fs/ext2fs.h b/lib/ext2fs/ext2fs.h
index a06f57e..93c8360 100644
--- a/lib/ext2fs/ext2fs.h
+++ b/lib/ext2fs/ext2fs.h
@@ -1374,6 +1374,10 @@
 errcode_t ext2fs_unlink(ext2_filsys fs, ext2_ino_t dir, const char *name,
 			ext2_ino_t ino, int flags);
 
+/* symlink.c */
+errcode_t ext2fs_symlink(ext2_filsys fs, ext2_ino_t parent, ext2_ino_t ino,
+			 const char *name, char *target);
+
 /* mmp.c */
 errcode_t ext2fs_mmp_read(ext2_filsys fs, blk64_t mmp_blk, void *buf);
 errcode_t ext2fs_mmp_write(ext2_filsys fs, blk64_t mmp_blk, void *buf);