Add session ref-counting and clean up TLS resume client

- Switch to wolfSSL_get1_session() to take a reference to the session
- Explicitly null out ssl after free to avoid double-free on exit path
- Always free WOLFSSL_SESSION regardless of OPENSSL_EXTRA define

Author: julek-wolfssl

tls/client-tls-resume.c

@@ -174,14 +174,14 @@ int main(int argc, char** argv)
 
 
     /* Save the session */
-    session = wolfSSL_get_session(ssl);
+    session = wolfSSL_get1_session(ssl);
 
     /* Close the socket */
     wolfSSL_free(ssl);
+    ssl = NULL;
     close(sockfd);
 
 
-
     /* --------------------------------------- *
      * we are now disconnected from the server *
      * --------------------------------------- */
@@ -275,10 +275,8 @@ int main(int argc, char** argv)
     /* Cleanup and return */
     if (ssl)
         wolfSSL_free(ssl);      /* Free the wolfSSL object              */
-#ifdef OPENSSL_EXTRA   
     if (session)
         wolfSSL_SESSION_free(session);
-#endif    
     if (sockfd != SOCKET_INVALID)
         close(sockfd);          /* Close the socket   */
     if (ctx)