9p: Do a couple of cleanups

Do a couple of cleanups to 9p:

(1) Remove a couple of unused variables.

(2) Turn a BUG_ON() into a warning, consolidate with another warning and
make the warning message include the inode number rather than
whatever's in i_private (which will get hashed anyway).

Suggested-by: Dominique Martinet <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]/
Signed-off-by: David Howells <[e-mail]>
Acked-by: Dominique Martinet <[e-mail]>
cc: Eric Van Hensbergen <[e-mail]>
cc: Latchesar Ionkov <[e-mail]>
cc: Christian Schoenebeck <[e-mail]>
cc: [e-mail]
cc: [e-mail]
cc: [e-mail]

fs/9p/vfs_addr.c

···
 
 static void v9fs_upload_to_server(struct netfs_io_subrequest *subreq)
 {
-	struct inode *inode = subreq->rreq->inode;
-	struct v9fs_inode __maybe_unused *v9inode = V9FS_I(inode);
 	struct p9_fid *fid = subreq->rreq->netfs_priv;
 	int err;
 
···
 
 	if (file) {
 		fid = file->private_data;
-		BUG_ON(!fid);
+		if (!fid)
+			goto no_fid;
 		p9_fid_get(fid);
 	} else {
 		fid = v9fs_fid_find_inode(rreq->inode, writing, INVALID_UID, true);
-		if (!fid) {
-			WARN_ONCE(1, "folio expected an open fid inode->i_private=%p\n",
-				  rreq->inode->i_private);
-			return -EINVAL;
-		}
+		if (!fid)
+			goto no_fid;
 	}
 
 	/* we might need to read from a fid that was opened write-only
···
 	WARN_ON(rreq->origin == NETFS_READ_FOR_WRITE && !(fid->mode & P9_ORDWR));
 	rreq->netfs_priv = fid;
 	return 0;
+
+no_fid:
+	WARN_ONCE(1, "folio expected an open fid inode->i_ino=%lx\n",
+		  rreq->inode->i_ino);
+	return -EINVAL;
 }
 
 /**