Add expected size to nonce generation test

Also add unneeded copy-paste in the test descriptions.

Signed-off-by: Paul Elliott <paul.elliott@arm.com>
diff --git a/tests/suites/test_suite_psa_crypto.function b/tests/suites/test_suite_psa_crypto.function
index 5f36230..b5fe5e7 100644
--- a/tests/suites/test_suite_psa_crypto.function
+++ b/tests/suites/test_suite_psa_crypto.function
@@ -3699,6 +3699,7 @@
 void aead_multipart_generate_nonce( int key_type_arg, data_t *key_data,
                                     int alg_arg,
                                     int nonce_len,
+                                    int expected_generated_len_arg,
                                     data_t *additional_data,
                                     data_t *input_data,
                                     int expected_status_arg )
@@ -3712,6 +3713,7 @@
     psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT;
     psa_status_t status = PSA_ERROR_GENERIC_ERROR;
     size_t nonce_generated_len = 0;
+    size_t expected_generated_len = expected_generated_len_arg;
     unsigned char *output_data = NULL;
     unsigned char *final_data = NULL;
     size_t output_size = 0;
@@ -3764,6 +3766,8 @@
 
     TEST_ASSERT( status == expected_status_arg );
 
+    TEST_EQUAL( nonce_generated_len, expected_generated_len );
+
     if( expected_status_arg == PSA_SUCCESS )
     {