Refactor record size limit extension handling

Signed-off-by: Waleed Elmelegy <waleed.elmelegy@arm.com>
diff --git a/tests/suites/test_suite_ssl.function b/tests/suites/test_suite_ssl.function
index 05571a1..8a03d1b 100644
--- a/tests/suites/test_suite_ssl.function
+++ b/tests/suites/test_suite_ssl.function
@@ -2096,6 +2096,10 @@
     }
 #endif /* MBEDTLS_SSL_PROTO_TLS1_3 */
 
+#if defined(MBEDTLS_SSL_RECORD_SIZE_LIMIT)
+    TEST_ASSERT(original.record_size_limit == restored.record_size_limit);
+#endif
+
 exit:
     mbedtls_ssl_session_free(&original);
     mbedtls_ssl_session_free(&restored);