Add missing initialisation to setup test.
@@ -4181,6 +4181,8 @@ void aead_multipart_setup( int key_type_arg, data_t *key_data,
PSA_ASSERT( psa_import_key( &attributes, key_data->x, key_data->len,
&key ) );
+ operation = psa_aead_operation_init( );
+
mbedtls_test_set_step( 0 );
status = psa_aead_encrypt_setup( &operation, key, alg );
