Aligh update buffer test variables with psa naming

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 5fb7086..e01c495 100644
--- a/tests/suites/test_suite_psa_crypto.function
+++ b/tests/suites/test_suite_psa_crypto.function
@@ -3878,7 +3878,7 @@
 /* BEGIN_CASE */
 void aead_multipart_update_buffer_test( int key_type_arg, data_t *key_data,
                                        int alg_arg,
-                                       int buffer_size,
+                                       int output_size_arg,
                                        data_t *nonce,
                                        data_t *additional_data,
                                        data_t *input_data,
@@ -3892,10 +3892,11 @@
     psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT;
     psa_status_t status = PSA_ERROR_GENERIC_ERROR;
     psa_status_t expected_status = expected_status_arg;
-    unsigned char *output_data = NULL;
-    unsigned char *final_data = NULL;
-    size_t finish_output_size = 0;
-    size_t output_length = 0;
+    unsigned char *output = NULL;
+    unsigned char *ciphertext = NULL;
+    size_t output_size = output_size_arg;
+    size_t ciphertext_size = 0;
+    size_t ciphertext_length = 0;
     size_t tag_length = 0;
     uint8_t tag_buffer[PSA_AEAD_TAG_MAX_SIZE];
 
@@ -3910,13 +3911,11 @@
 
     PSA_ASSERT( psa_get_key_attributes( key, &attributes ) );
 
-    ASSERT_ALLOC( output_data, buffer_size );
+    ASSERT_ALLOC( output, output_size );
 
-    finish_output_size = PSA_AEAD_FINISH_OUTPUT_SIZE( key_type, alg );
+    ciphertext_size = PSA_AEAD_FINISH_OUTPUT_SIZE( key_type, alg );
 
-    TEST_ASSERT( finish_output_size <= PSA_AEAD_FINISH_OUTPUT_MAX_SIZE );
-
-    ASSERT_ALLOC( final_data, finish_output_size );
+    ASSERT_ALLOC( ciphertext, ciphertext_size );
 
     operation = psa_aead_operation_init( );
 
@@ -3939,22 +3938,22 @@
                                     additional_data->len ) );
 
     status = psa_aead_update( &operation, input_data->x, input_data->len,
-                              output_data, buffer_size, &output_length );
+                              output, output_size, &ciphertext_length );
 
     TEST_EQUAL( status, expected_status );
 
     if( expected_status == PSA_SUCCESS )
     {
         /* Ensure we can still complete operation. */
-        PSA_ASSERT( psa_aead_finish( &operation, final_data, finish_output_size,
-                                     &output_length, tag_buffer,
+        PSA_ASSERT( psa_aead_finish( &operation, ciphertext, ciphertext_size,
+                                     &ciphertext_length, tag_buffer,
                                      PSA_AEAD_TAG_MAX_SIZE, &tag_length ) );
     }
 
 exit:
     psa_destroy_key( key );
-    mbedtls_free( output_data );
-    mbedtls_free( final_data );
+    mbedtls_free( output );
+    mbedtls_free( ciphertext );
     psa_aead_abort( &operation );
     PSA_DONE( );
 }