mbedtls_mpi_exp_mod test: don't read RR from test data

Remove the RR parameter to the mbedtls_mpi_exp_mod test function.
It was never used in the test data, so there is no loss of functionality.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/tests/suites/test_suite_mpi.function b/tests/suites/test_suite_mpi.function
index 1d2da29..8a46066 100644
--- a/tests/suites/test_suite_mpi.function
+++ b/tests/suites/test_suite_mpi.function
@@ -985,8 +985,7 @@
 /* BEGIN_CASE */
 void mbedtls_mpi_exp_mod( int radix_A, char * input_A, int radix_E,
                           char * input_E, int radix_N, char * input_N,
-                          int radix_RR, char * input_RR, int radix_X,
-                          char * input_X, int div_result )
+                          int radix_X, char * input_X, int div_result )
 {
     mbedtls_mpi A, E, N, RR, Z, X;
     int res;
@@ -998,9 +997,6 @@
     TEST_ASSERT( mbedtls_test_read_mpi( &N, radix_N, input_N ) == 0 );
     TEST_ASSERT( mbedtls_test_read_mpi( &X, radix_X, input_X ) == 0 );
 
-    if( strlen( input_RR ) )
-        TEST_ASSERT( mbedtls_test_read_mpi( &RR, radix_RR, input_RR ) == 0 );
-
     res = mbedtls_mpi_exp_mod( &Z, &A, &E, &N, &RR );
     TEST_ASSERT( res == div_result );
     if( res == 0 )