Remove redundant IP length definition

REDIS_CLUSTER_IPLEN had the same value as
REDIS_IP_STR_LEN.  They were both #define'd
to the same INET6_ADDRSTRLEN.

src/cluster.c

@@ -928,11 +928,11 @@ int clusterStartHandshake(char *ip, int port) {
     if (sa.ss_family == AF_INET)
         inet_ntop(AF_INET,
             (void*)&(((struct sockaddr_in *)&sa)->sin_addr),
-            norm_ip,REDIS_CLUSTER_IPLEN);
+            norm_ip,REDIS_IP_STR_LEN);
     else
         inet_ntop(AF_INET6,
             (void*)&(((struct sockaddr_in6 *)&sa)->sin6_addr),
-            norm_ip,REDIS_CLUSTER_IPLEN);
+            norm_ip,REDIS_IP_STR_LEN);
 
     if (clusterHandshakeInProgress(norm_ip,port)) {
         errno = EAGAIN;
@@ -1034,7 +1034,7 @@ void clusterProcessGossipSection(clusterMsg *hdr, clusterLink *link) {
 
 /* IP -> string conversion. 'buf' is supposed to at least be 46 bytes. */
 void nodeIp2String(char *buf, clusterLink *link) {
-    anetPeerToString(link->fd, buf, REDIS_CLUSTER_IPLEN, NULL);
+    anetPeerToString(link->fd, buf, REDIS_IP_STR_LEN, NULL);
 }
 
 /* Update the node address to the IP address that can be extracted

src/cluster.h

@@ -10,7 +10,6 @@
 #define REDIS_CLUSTER_FAIL 1        /* The cluster can't work */
 #define REDIS_CLUSTER_NAMELEN 40    /* sha1 hex length */
 #define REDIS_CLUSTER_PORT_INCR 10000 /* Cluster port = baseport + PORT_INCR */
-#define REDIS_CLUSTER_IPLEN INET6_ADDRSTRLEN /* IPv6 address string length */
 
 /* The following defines are amunt of time, sometimes expressed as
  * multiplicators of the node timeout value (when ending with MULT). */