filesystems: add missing nlink wrappers

Replace direct i_nlink updates with the respective updater function
(inc_nlink, drop_nlink, clear_nlink, inode_dec_link_count).

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
diff --git a/fs/reiserfs/inode.c b/fs/reiserfs/inode.c
index 9b0d4b78..c425441 100644
--- a/fs/reiserfs/inode.c
+++ b/fs/reiserfs/inode.c
@@ -1444,7 +1444,7 @@
 		/* a stale NFS handle can trigger this without it being an error */
 		pathrelse(&path_to_sd);
 		reiserfs_make_bad_inode(inode);
-		inode->i_nlink = 0;
+		clear_nlink(inode);
 		return;
 	}
 
@@ -1987,7 +1987,7 @@
 	make_bad_inode(inode);
 
       out_inserted_sd:
-	inode->i_nlink = 0;
+	clear_nlink(inode);
 	th->t_trans_id = 0;	/* so the caller can't use this handle later */
 	unlock_new_inode(inode); /* OK to do even if we hadn't locked it */
 	iput(inode);