Update group ext debug message in ssl_tls13_server.c

Signed-off-by: Xiaokang Qian <xiaokang.qian@arm.com>
diff --git a/library/ssl_tls13_server.c b/library/ssl_tls13_server.c
index aaefe58..bc874be 100644
--- a/library/ssl_tls13_server.c
+++ b/library/ssl_tls13_server.c
@@ -1554,7 +1554,7 @@
                     ssl, p, extension_data_end);
                 if (ret != 0) {
                     MBEDTLS_SSL_DEBUG_RET(
-                        1, "mbedtls_ssl_parse_supported_groups_ext", ret);
+                        1, "ssl_tls13_parse_supported_groups_ext", ret);
                     return ret;
                 }