Check all of the limbs of result

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 1a6302f..3b01e4d 100644
--- a/tests/suites/test_suite_ecp.function
+++ b/tests/suites/test_suite_ecp.function
@@ -1563,7 +1563,7 @@
     mbedtls_mpi_uint *A_inverse = NULL;
     mbedtls_mpi_uint *A = NULL;
     mbedtls_mpi_uint *bufx = NULL;
-    const mbedtls_mpi_uint one = 1;
+    const mbedtls_mpi_uint one[2] = {1, 0};
 
     ((void) iret);
 
@@ -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(mbedtls_mpi_uint)), 0);
+    TEST_EQUAL(memcmp(bufx, one, sizeof(one)), 0);
 
 
 exit: