Cluster: abort on port too high error.

It also fixes multi-line comment style to be consistent with the rest of
the code base.

Related to #1555.

src/cluster.c

@@ -331,15 +331,15 @@ void clusterInit(void) {
     server.cfd_count = 0;
 
     /* Port sanity check II
-       The other handshake port check is triggered too late to stop
-       us from trying to use a too-high cluster port number.
-    */
+     * The other handshake port check is triggered too late to stop
+     * us from trying to use a too-high cluster port number. */
     if (server.port > (65535-REDIS_CLUSTER_PORT_INCR)) {
         redisLog(REDIS_WARNING, "Redis port number too high. "
                    "Cluster communication port is 10,000 port "
                    "numbers higher than your Redis port. "
                    "Your Redis port number must be "
                    "lower than 55535.");
+        exit(1);
     }
 
     if (listenToPort(server.port+REDIS_CLUSTER_PORT_INCR,