writeback: add a __releases annoation to wbc_attach_and_unlock_inode

This shuts up a sparse lock context tracking warning.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20241112054403.1470586-2-hch@lst.de
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>

Author: Christoph Hellwig

fs/fs-writeback.c

@@ -733,6 +733,7 @@ bool cleanup_offline_cgwb(struct bdi_writeback *wb)
  */
 void wbc_attach_and_unlock_inode(struct writeback_control *wbc,
 				 struct inode *inode)
+	__releases(&inode->i_lock)
 {
 	if (!inode_cgwb_enabled(inode)) {
 		spin_unlock(&inode->i_lock);