Use more explicit way of copying pointer value to a buffer

The code initializing GMK Counter uses the group pointer value as extra
entropy and to distinguish different group instances. Some static
analyzers complain about the sizeof(pointer) with memcpy, so use a more
explicit type casting to make it more obvious what the code is doing.

Signed-hostap: Jouni Malinen <j@w1.fi>

src/ap/wpa_auth.c

@@ -282,8 +282,9 @@ static void wpa_auth_pmksa_free_cb(struct rsn_pmksa_cache_entry *entry,
 static int wpa_group_init_gmk_and_counter(struct wpa_authenticator *wpa_auth,
 					  struct wpa_group *group)
 {
-	u8 buf[ETH_ALEN + 8 + sizeof(group)];
+	u8 buf[ETH_ALEN + 8 + sizeof(unsigned long)];
 	u8 rkey[32];
+	unsigned long ptr;
 
 	if (random_get_bytes(group->GMK, WPA_GMK_LEN) < 0)
 		return -1;
@@ -295,7 +296,8 @@ static int wpa_group_init_gmk_and_counter(struct wpa_authenticator *wpa_auth,
 	 */
 	os_memcpy(buf, wpa_auth->addr, ETH_ALEN);
 	wpa_get_ntp_timestamp(buf + ETH_ALEN);
-	os_memcpy(buf + ETH_ALEN + 8, &group, sizeof(group));
+	ptr = (unsigned long) group;
+	os_memcpy(buf + ETH_ALEN + 8, &ptr, sizeof(ptr));
 	if (random_get_bytes(rkey, sizeof(rkey)) < 0)
 		return -1;