RDMA: Fix listener priv opaque pointer (valkey-io#1194)

struct connListener.priv should be used by connection type specific
data, static local listener data should not use this.

A RDMA config structure is going to be introduced in the next step:

```
typedef struct serverRdmaContextConfig {
    char *bindaddr;
    int bindaddr_count;
    int port;
    int rx_size;
    int comp_vector;
    ...
} serverRdmaContextConfig;
```

Then a builtin RDMA will be supported.

Signed-off-by: zhenwei pi <[email protected]>

src/rdma.c

@@ -127,6 +127,8 @@ typedef struct rdma_listener {
  * handler into pending list */
 static list *pending_list;
 
+static rdma_listener *rdma_listeners;
+
 static ConnectionType CT_RDMA;
 
 static int valkey_rdma_rx_size = VALKEY_RDMA_DEFAULT_RX_SIZE;
@@ -748,7 +750,7 @@ static rdma_listener *rdmaFdToListener(connListener *listener, int fd) {
     for (int i = 0; i < listener->count; i++) {
         if (listener->fd[i] != fd) continue;
 
-        return (rdma_listener *)listener->priv + i;
+        return &rdma_listeners[i];
     }
 
     return NULL;
@@ -1537,7 +1539,7 @@ int connRdmaListen(connListener *listener) {
         bindaddr = default_bindaddr;
     }
 
-    listener->priv = rdma_listener = zcalloc_num(bindaddr_count, sizeof(*rdma_listener));
+    rdma_listeners = rdma_listener = zcalloc_num(bindaddr_count, sizeof(*rdma_listener));
     for (j = 0; j < bindaddr_count; j++) {
         char *addr = bindaddr[j];
         int optional = *addr == '-';
@@ -1757,13 +1759,14 @@ static int rdmaChangeListener(void) {
 
         aeDeleteFileEvent(server.el, listener->fd[i], AE_READABLE);
         listener->fd[i] = -1;
-        struct rdma_listener *rdma_listener = (struct rdma_listener *)listener->priv + i;
+        struct rdma_listener *rdma_listener = &rdma_listeners[i];
         rdma_destroy_id(rdma_listener->cm_id);
         rdma_destroy_event_channel(rdma_listener->cm_channel);
     }
 
     listener->count = 0;
-    zfree(listener->priv);
+    zfree(rdma_listeners);
+    rdma_listeners = NULL;
 
     closeListener(listener);