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>

fs/coda/dir.c

@@ -340,7 +340,7 @@ static int coda_rmdir(struct inode *dir, struct dentry *de)
 	if (!error) {
 		/* VFS may delete the child */
 		if (de->d_inode)
-		    de->d_inode->i_nlink = 0;
+			clear_nlink(de->d_inode);
 
 		/* fix the link count of the parent */
 		coda_dir_drop_nlink(dir);