TLS UNSUPPORTED_EXTENSION error code changes

Signed-off-by: Dave Rodgman <dave.rodgman@arm.com>
diff --git a/library/ssl_cli.c b/library/ssl_cli.c
index 7fedf17..b977e5b 100644
--- a/library/ssl_cli.c
+++ b/library/ssl_cli.c
@@ -1365,7 +1365,7 @@
         mbedtls_ssl_send_alert_message(
             ssl,
             MBEDTLS_SSL_ALERT_LEVEL_FATAL,
-            MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
+            MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_EXT );
         return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
     }
 
@@ -1391,7 +1391,7 @@
         mbedtls_ssl_send_alert_message(
             ssl,
             MBEDTLS_SSL_ALERT_LEVEL_FATAL,
-            MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
+            MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_EXT );
         return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
     }
 
@@ -1416,7 +1416,7 @@
         mbedtls_ssl_send_alert_message(
             ssl,
             MBEDTLS_SSL_ALERT_LEVEL_FATAL,
-            MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
+            MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_EXT );
         return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
     }
 
@@ -1522,7 +1522,7 @@
         mbedtls_ssl_send_alert_message(
             ssl,
             MBEDTLS_SSL_ALERT_LEVEL_FATAL,
-            MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
+            MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_EXT );
         return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO );
     }