uninitialised variable crashes in bgpd config parser

[Jonathan Gray]

Index: parse.y
===================================================================
RCS file: /cvs/src/usr.sbin/bgpd/parse.y,v
retrieving revision 1.315
diff -u -p -r1.315 parse.y
--- parse.y     21 Aug 2017 14:41:22 -0000      1.315
+++ parse.y     19 Oct 2017 05:32:03 -0000
@@ -3181,7 +3181,7 @@ parseextcommunity(struct filter_extcommu
        switch (type) {
        case -1:
                if ((p = strchr(s, ':')) == NULL) {
-                       yyerror("Bad ext-community %s is %s", s, errstr);
+                       yyerror("Bad ext-community %s", s);
                        return (-1);
                }
                *p++ = '\0';
@@ -3239,7 +3239,7 @@ parseextcommunity(struct filter_extcommu
                else if (strcmp(s, "not-found") == 0)
                        c->data.ext_opaq = EXT_COMMUNITY_OVS_NOTFOUND;
                else {
-                       yyerror("Bad ext-community %s is %s", s, errstr);
+                       yyerror("Bad ext-community %s", s);
                        return (-1);
                }
                break;