qnx6_lookup: switch to d_splice_alias()

... and hash negative lookups
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/qnx6/namei.c

@@ -29,15 +29,11 @@ struct dentry *qnx6_lookup(struct inode *dir, struct dentry *dentry,
 	if (ino) {
 		foundinode = qnx6_iget(dir->i_sb, ino);
 		qnx6_put_page(page);
-		if (IS_ERR(foundinode)) {
+		if (IS_ERR(foundinode))
 			pr_debug("lookup->iget ->  error %ld\n",
 				 PTR_ERR(foundinode));
-			return ERR_CAST(foundinode);
-		}
 	} else {
 		pr_debug("%s(): not found %s\n", __func__, name);
-		return NULL;
 	}
-	d_add(dentry, foundinode);
-	return NULL;
+	return d_splice_alias(foundinode, dentry);
 }