Make "rndc zonestatus" output for mirror zones different than for regular slave zones

Replace "type: slave" with "type: mirror" in "rndc zonestatus" output
for mirror zones in order to enable the user to tell a regular slave
zone and a mirror zone apart.

bin/named/server.c

@@ -13849,7 +13849,7 @@ named_server_zonestatus(named_server_t *server, isc_lex_t *lex,
 		type = "master";
 		break;
 	case dns_zone_slave:
-		type = "slave";
+		type = dns_zone_ismirror(zone) ? "mirror" : "slave";
 		break;
 	case dns_zone_stub:
 		type = "stub";

bin/tests/system/mirror/clean.sh

@@ -20,3 +20,4 @@ rm -f */jn-*
 rm -f */named.memstats
 rm -f */named.run
 rm -f dig.out.*
+rm -f rndc.out.*

bin/tests/system/mirror/tests.sh

@@ -354,5 +354,13 @@ grep "initially-unavailable.*sending notifies" ns3/named.run > /dev/null && ret=
 if [ $ret != 0 ]; then echo_i "failed"; fi
 status=`expr $status + $ret`
 
+n=`expr $n + 1`
+echo_i "checking output of \"rndc zonestatus\" for a mirror zone ($n)"
+ret=0
+$RNDCCMD 10.53.0.3 zonestatus . > rndc.out.ns3.test$n 2>&1
+grep "type: mirror" rndc.out.ns3.test$n > /dev/null || ret=1
+if [ $ret != 0 ]; then echo_i "failed"; fi
+status=`expr $status + $ret`
+
 echo_i "exit status: $status"
 [ $status -eq 0 ] || exit 1