fuse: add fuse_conn->release()

Add fuse_conn->release() so that fuse_conn can be embedded in other
structures.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index eb488d4..5e64b81 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -465,6 +465,9 @@
 
 	/** Version counter for attribute changes */
 	u64 attr_version;
+
+	/** Called on final put */
+	void (*release)(struct fuse_conn *);
 };
 
 static inline struct fuse_conn *get_fuse_conn_super(struct super_block *sb)