dma_buf_getfile(): don't bother with ->f_flags reassignments

just pass the already sanitized value to alloc_file_pseudo().
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

drivers/dma-buf/dma-buf.c

@@ -531,11 +531,11 @@ static struct file *dma_buf_getfile(struct dma_buf *dmabuf, int flags)
 	 * value.
 	 */
 	inode->i_ino = atomic64_add_return(1, &dmabuf_inode);
+	flags &= O_ACCMODE | O_NONBLOCK;
 	file = alloc_file_pseudo(inode, dma_buf_mnt, "dmabuf",
 				 flags, &dma_buf_fops);
 	if (IS_ERR(file))
 		goto err_alloc_file;
-	file->f_flags = flags & (O_ACCMODE | O_NONBLOCK);
 	file->private_data = dmabuf;
 	file->f_path.dentry->d_fsdata = dmabuf;