Modifies tests in RSA test suite

Tests for mbedtls_rsa_rsassa_pss_sign in
test_suite_rsa.function have been modified to
allow for upcoming removal of mode param.

Signed-off-by: Thomas Daubney <thomas.daubney@arm.com>
diff --git a/tests/suites/test_suite_rsa.function b/tests/suites/test_suite_rsa.function
index e70faac..7c7d8f9 100644
--- a/tests/suites/test_suite_rsa.function
+++ b/tests/suites/test_suite_rsa.function
@@ -249,27 +249,22 @@
 
     TEST_INVALID_PARAM_RET( MBEDTLS_ERR_RSA_BAD_INPUT_DATA,
                             mbedtls_rsa_rsassa_pss_sign( NULL, NULL, NULL,
-                                                         valid_mode,
+                                                         MBEDTLS_RSA_PRIVATE,
                                                          0, sizeof( buf ), buf,
                                                          buf ) );
     TEST_INVALID_PARAM_RET( MBEDTLS_ERR_RSA_BAD_INPUT_DATA,
                             mbedtls_rsa_rsassa_pss_sign( &ctx, NULL, NULL,
-                                                         invalid_mode,
-                                                         0, sizeof( buf ), buf,
-                                                         buf ) );
-    TEST_INVALID_PARAM_RET( MBEDTLS_ERR_RSA_BAD_INPUT_DATA,
-                            mbedtls_rsa_rsassa_pss_sign( &ctx, NULL, NULL,
-                                                         valid_mode,
+                                                         MBEDTLS_RSA_PRIVATE,
                                                          0, sizeof( buf ), NULL,
                                                          buf ) );
     TEST_INVALID_PARAM_RET( MBEDTLS_ERR_RSA_BAD_INPUT_DATA,
                             mbedtls_rsa_rsassa_pss_sign( &ctx, NULL, NULL,
-                                                         valid_mode,
+                                                         MBEDTLS_RSA_PRIVATE,
                                                          0, sizeof( buf ), buf,
                                                          NULL ) );
     TEST_INVALID_PARAM_RET( MBEDTLS_ERR_RSA_BAD_INPUT_DATA,
                             mbedtls_rsa_rsassa_pss_sign( &ctx, NULL, NULL,
-                                                         valid_mode,
+                                                         MBEDTLS_RSA_PRIVATE,
                                                          MBEDTLS_MD_SHA1,
                                                          0, NULL,
                                                          buf ) );