Tests: Fix bison stability.

test_regress/t/t_pp_circdef_bad.out

@@ -1,3 +0,0 @@
-%Error: t/t_pp_circdef_bad.v:14:21985: Recursive `define or other nested inclusion
-%Error: t/t_pp_circdef_bad.v:14:3009: syntax error, unexpected $end, expecting TYPE-IDENTIFIER
-%Error: Exiting due to

test_regress/t/t_pp_circdef_bad.pl

@@ -12,7 +12,8 @@ scenarios(vlt => 1);
 
 lint(
     fails => 1,
-    expect_filename => $Self->{golden_filename},
+    # EOF result varies with Bison version, so can't use .out
+    expect => qr/define or other nested inclusion/,
     );
 
 ok(1);