pidfs: remove unused members from struct pidfs_inode

We've moved persistent information to struct pid.
So there's no need for these anymore.

Link: https://lore.kernel.org/20250618-work-pidfs-persistent-v2-6-98f3456fd552@kernel.org
Reviewed-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>

fs/pidfs.c

@@ -46,8 +46,6 @@ struct pidfs_attr {
 };
 
 struct pidfs_inode {
-	struct pidfs_exit_info __pei;
-	struct pidfs_exit_info *exit_info;
 	struct inode vfs_inode;
 };
 
@@ -696,9 +694,6 @@ static struct inode *pidfs_alloc_inode(struct super_block *sb)
 	if (!pi)
 		return NULL;
 
-	memset(&pi->__pei, 0, sizeof(pi->__pei));
-	pi->exit_info = NULL;
-
 	return &pi->vfs_inode;
 }