Fix for CID 299536 possible null dereference

src/ssl.c

@@ -29974,13 +29974,17 @@ static void SESSION_ex_data_cache_update(WOLFSSL_SESSION* session, int idx,
         #endif
             ) {
             if (get) {
+                if (getRet) {
                     *getRet = wolfSSL_CRYPTO_get_ex_data(
                         &cacheSession->ex_data, idx);
                 }
+            }
             else {
+                if (setRet) {
                     *setRet = wolfSSL_CRYPTO_set_ex_data(
                         &cacheSession->ex_data, idx, data);
                 }
+            }
             foundCache = 1;
             break;
         }