mbedtls_test_read_mpi_core: allow odd number of hex digits

Test functions must now take a char* argument rather than data_t*. This does
not affect existing test data.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/tests/suites/test_suite_mpi.data b/tests/suites/test_suite_mpi.data
index be4c056..2a1e48f 100644
--- a/tests/suites/test_suite_mpi.data
+++ b/tests/suites/test_suite_mpi.data
@@ -595,13 +595,13 @@
 mpi_cmp_mpi:"-1230000000000000000":"0":-1
 
 mbedtls_mpi_core_lt_ct: x=y (1 limb)
-mpi_core_lt_ct:"02B5":"02B5":0
+mpi_core_lt_ct:"2B5":"2B5":0
 
 mbedtls_mpi_core_lt_ct: x>y (1 limb)
-mpi_core_lt_ct:"02B5":"02B4":0
+mpi_core_lt_ct:"2B5":"2B4":0
 
 mbedtls_mpi_core_lt_ct: x<y (1 limb)
-mpi_core_lt_ct:"02B5":"02B6":1
+mpi_core_lt_ct:"2B5":"2B6":1
 
 mbedtls_mpi_core_lt_ct: x=y (0 limbs)
 mpi_core_lt_ct:"":"":0
@@ -667,7 +667,7 @@
 mpi_core_lt_ct:"000000FF":"FFFFFFFF":1
 
 mbedtls_mpi_core_lt_ct: x<y, zero vs non-zero MS limb
-mpi_core_lt_ct:"00FFFFFFFFFFFFFFFF":"01FFFFFFFFFFFFFFFF":1
+mpi_core_lt_ct:"0FFFFFFFFFFFFFFFF":"1FFFFFFFFFFFFFFFF":1
 
 mbedtls_mpi_core_lt_ct: x>y, equal MS limbs
 mpi_core_lt_ct:"EEFFFFFFFFFFFFFFFF":"EEFFFFFFFFFFFFFFF1":0
diff --git a/tests/suites/test_suite_mpi.function b/tests/suites/test_suite_mpi.function
index d450197..2528b9c 100644
--- a/tests/suites/test_suite_mpi.function
+++ b/tests/suites/test_suite_mpi.function
@@ -728,7 +728,7 @@
 /* END_CASE */
 
 /* BEGIN_CASE */
-void mpi_core_lt_ct( data_t * input_X, data_t * input_Y, int exp_ret )
+void mpi_core_lt_ct( char *input_X, char *input_Y, int exp_ret )
 {
     mbedtls_mpi_uint *X = NULL;
     size_t X_limbs;