Revert last change, it seems that a lot of software (including our own

lint) uses yydebug even when YYDEBUG is not defined.

usr.bin/yacc/skeleton.c

@@ -16,7 +16,7 @@ char *banner[] =
 {
     "#ifndef lint",
     "/*static char yysccsid[] = \"from: @(#)yaccpar	1.9 (Berkeley) 02/21/93\";*/",
-    "static char yyrcsid[] = \"$Id: skeleton.c,v 1.5 1995/08/24 00:45:23 jtc Exp $\";",
+    "static char yyrcsid[] = \"$Id: skeleton.c,v 1.6 1995/09/07 17:34:04 jtc Exp $\";",
     "#endif",
     "#define YYBYACC 1",
     "#define YYMAJOR 1",
@@ -60,9 +60,7 @@ char *header[] =
     "#define YYMAXDEPTH 500",
     "#endif",
     "#endif",
-    "#if YYDEBUG",
     "int yydebug;",
-    "#endif",
     "int yynerrs;",
     "int yyerrflag;",
     "int yychar;",