configfs: fix memleak in configfs_release_bin_file

When reading binary attributes in progress, buffer->bin_buffer is setup in
configfs_read_bin_file() but never freed.

Fixes: 03607ace ("configfs: implement binary attributes")
Signed-off-by: NChung-Chiang Cheng <cccheng@synology.com>
[hch: move the vfree rather than duplicating it]
Signed-off-by: NChristoph Hellwig <hch@lst.de>

fs/configfs/file.c

@@ -407,13 +407,13 @@ static int configfs_release_bin_file(struct inode *inode, struct file *file)
 					buffer->bin_buffer_size);
 		}
 		up_read(&frag->frag_sem);
-		/* vfree on NULL is safe */
-		vfree(buffer->bin_buffer);
-		buffer->bin_buffer = NULL;
-		buffer->bin_buffer_size = 0;
-		buffer->needs_read_fill = 1;
 	}
 
+	vfree(buffer->bin_buffer);
+	buffer->bin_buffer = NULL;
+	buffer->bin_buffer_size = 0;
+	buffer->needs_read_fill = 1;
+
 	configfs_release(inode, file);
 	return 0;
 }