wrappers for ->i_mutex access

parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested},
inode_foo(inode) being mutex_foo(&inode->i_mutex).

Please, use those for access to ->i_mutex; over the coming cycle
->i_mutex will become rwsem, with ->lookup() done with it held
only shared.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/hfsplus/dir.c

@@ -284,9 +284,9 @@ static int hfsplus_dir_release(struct inode *inode, struct file *file)
 {
 	struct hfsplus_readdir_data *rd = file->private_data;
 	if (rd) {
-		mutex_lock(&inode->i_mutex);
+		inode_lock(inode);
 		list_del(&rd->list);
-		mutex_unlock(&inode->i_mutex);
+		inode_unlock(inode);
 		kfree(rd);
 	}
 	return 0;