Fix broken tests due to changed error code

Introduced in 5246ee5c59906fc4b021ceab63f09afdedbc66b8
diff --git a/tests/suites/test_suite_ecp.function b/tests/suites/test_suite_ecp.function
index 1f04d67..50a95e1 100644
--- a/tests/suites/test_suite_ecp.function
+++ b/tests/suites/test_suite_ecp.function
@@ -472,7 +472,7 @@
     TEST_ASSERT( ecp_tls_write_point( &grp, &grp.G,
                     POLARSSL_ECP_PF_COMPRESSED, &olen, buf, 256 ) == 0 );
     TEST_ASSERT( ecp_tls_read_point( &grp, &pt, &vbuf, olen )
-                 == POLARSSL_ERR_ECP_BAD_INPUT_DATA );
+                 == POLARSSL_ERR_ECP_FEATURE_UNAVAILABLE );
     TEST_ASSERT( vbuf == buf + olen );
 
     memset( buf, 0x00, sizeof( buf ) ); vbuf = buf;