fix comments and time_t type issues

Signed-off-by: Jerry Yu <jerry.h.yu@arm.com>
diff --git a/include/mbedtls/check_config.h b/include/mbedtls/check_config.h
index 5fe9849..b7ad7e9 100644
--- a/include/mbedtls/check_config.h
+++ b/include/mbedtls/check_config.h
@@ -843,6 +843,11 @@
 #error "MBEDTLS_SSL_TICKET_C defined, but not all prerequisites"
 #endif
 
+#if defined(MBEDTLS_SSL_TICKET_NONCE_LENGTH) && \
+    MBEDTLS_SSL_TICKET_NONCE_LENGTH >= 256
+#error "MBEDTLS_SSL_TICKET_NONCE_LENGTH must be less than 256"
+#endif
+
 #if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION) && \
         !defined(MBEDTLS_X509_CRT_PARSE_C)
 #error "MBEDTLS_SSL_SERVER_NAME_INDICATION defined, but not all prerequisites"