simplification: no null check is needed before delete

git-svn-id: svn://bind10.isc.org/svn/bind10/branches/jinmei-asio@1196 e5f2f494-b856-4b98-b285-d166d9295462

src/bin/auth/main.cc

@@ -379,18 +379,10 @@ main(int argc, char* argv[]) {
         ret = 1;
     }
 
-    if (udp4_server != NULL) {
-        delete udp4_server;
-    }
-    if (tcp4_server != NULL) {
-        delete tcp4_server;
-    }
-    if (udp6_server != NULL) {
-        delete udp6_server;
-    }
-    if (tcp6_server != NULL) {
-        delete tcp6_server;
-    }
+    delete udp4_server;
+    delete tcp4_server;
+    delete udp6_server;
+    delete tcp6_server;
 
     delete auth_server;
     return (ret);