ldomctl: parse.y: bail earlier on duplicate domains

[Klemens Nanni]

No functional change, just a tiny hoisting in the parser I'd like to
better reflect the order in which we parse the tokens.

If the given domain was already specified, don't bother allocating and
initializing it.

Drop the obvious comment while here.

OK?


Index: parse.y
===================================================================
RCS file: /cvs/src/usr.sbin/ldomctl/parse.y,v
retrieving revision 1.13
diff -u -p -r1.13 parse.y
--- parse.y     28 Nov 2019 18:40:42 -0000      1.13
+++ parse.y     30 Dec 2019 22:54:10 -0000
@@ -110,6 +110,12 @@ grammar            : /* empty */
                ;
 
 domain         : DOMAIN STRING optnl '{' optnl {
+                       struct domain *odomain;
+                       SIMPLEQ_FOREACH(odomain, &conf->domain_list, entry)
+                               if (strcmp(odomain->name, $2) == 0) {
+                                       yyerror("duplicate domain name: %s", 
$2);
+                                       YYERROR;
+                               }
                        domain = xzalloc(sizeof(struct domain));
                        domain->name = $2;
                        SIMPLEQ_INIT(&domain->vdisk_list);
@@ -118,13 +124,6 @@ domain             : DOMAIN STRING optnl '{' optnl 
                        SIMPLEQ_INIT(&domain->iodev_list);
                }
                    domainopts_l '}' {
-                       /* domain names need to be unique. */
-                       struct domain *odomain;
-                       SIMPLEQ_FOREACH(odomain, &conf->domain_list, entry)
-                               if (strcmp(odomain->name, $2) == 0) {
-                                       yyerror("duplicate domain name: %s", 
$2);
-                                       YYERROR;
-                               }
                        SIMPLEQ_INSERT_TAIL(&conf->domain_list, domain, entry);
                        domain = NULL;
                }