fix various issues

- typo error
- replace `ssl->hanshake` with handshake

Signed-off-by: Jerry Yu <jerry.h.yu@arm.com>
diff --git a/library/ssl_tls13_server.c b/library/ssl_tls13_server.c
index 597fbb7..3cd0310 100644
--- a/library/ssl_tls13_server.c
+++ b/library/ssl_tls13_server.c
@@ -1624,7 +1624,7 @@
     }
 
     MBEDTLS_SSL_PRINT_EXTS( 3, MBEDTLS_SSL_HS_CLIENT_HELLO,
-                            ssl->handshake->received_extensions );
+                            handshake->received_extensions );
 
     mbedtls_ssl_add_hs_hdr_to_checksum( ssl,
                                         MBEDTLS_SSL_HS_CLIENT_HELLO,