AuditLog: Improve code quality

This patch fix the following things:
* add const keyword when mutability is not required
* cast unused parameters to void to be more explicit
* add parenthesis for better readability of some expressions
* check the returning value of functions
* avoid implicit casting by using matching types

Change-Id: Ia3d8dfb34d6a0bfb36f0cfca1fe6db9a1820ca33
Signed-off-by: Hugues de Valon <hugues.devalon@arm.com>
diff --git a/secure_fw/services/audit_logging/audit_wrappers.c b/secure_fw/services/audit_logging/audit_wrappers.c
index 5640e5e..ec89cde 100644
--- a/secure_fw/services/audit_logging/audit_wrappers.c
+++ b/secure_fw/services/audit_logging/audit_wrappers.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, Arm Limited. All rights reserved.
+ * Copyright (c) 2018-2019, Arm Limited. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  *
@@ -16,8 +16,8 @@
 
 /*!@{*/
 enum psa_audit_err audit_core_retrieve_record_wrapper(
-                                const struct audit_core_retrieve_input *input_s,
-                                    struct audit_core_retrieve_output *output_s)
+                              const struct audit_core_retrieve_input *input_s,
+                              const struct audit_core_retrieve_output *output_s)
 {
     return audit_core_retrieve_record(input_s->record_index,
                                       input_s->buffer_size,