Compare final result with ASSERT_COMPARE

Signed-off-by: Xiaokang Qian <xiaokang.qian@arm.com>
diff --git a/tests/suites/test_suite_ecp.function b/tests/suites/test_suite_ecp.function
index 3b01e4d..bc2cd75 100644
--- a/tests/suites/test_suite_ecp.function
+++ b/tests/suites/test_suite_ecp.function
@@ -1592,7 +1592,7 @@
     TEST_EQUAL(mbedtls_mpi_mod_write(&rX, &m, (unsigned char *) bufx,
                                         limbs * sizeof(mbedtls_mpi_uint),
                                         MBEDTLS_MPI_MOD_EXT_REP_LE), 0);
-    TEST_EQUAL(memcmp(bufx, one, sizeof(one)), 0);
+    ASSERT_COMPARE(bufx, 2, one, 2);
 
 
 exit: