Fix tacacs local accounting break. (#18357)

Fix TACACS local accounting disabled when debug flag disabled.

#### Why I did it
TACACS local accounting use trace() method to output local accounting log, following PR disable trace log when debug flag disabled, 
#16482

Because test case issue, this regression not found. the issue only exists on master branch.

### How I did it
Fix TACACS local accounting disabled when debug flag disabled.

#### How to verify it
Pass all UT.
Fix TACACS accounting UT to prevent regression.

### Tested branch (Please provide the tested image version)

- [] SONiC.master-16482.360728-2c8b4066f

#### Description for the changelog
Fix TACACS local accounting disabled when debug flag disabled.

Author: liuh-80

src/tacacs/audisp/patches/0003-Add-local-accounting.patch

@@ -70,12 +70,12 @@ index 0000000..e23acec
 +#include "trace.h"
 +
 +/* Accounting log format. */
-+#define ACCOUNTING_LOG_FORMAT "Accounting: user: %s, tty: %s, host: %s, command: %s, type: %d, task ID: %d"
++#define ACCOUNTING_LOG_FORMAT "Audisp-tacplus: Accounting: user: %s, tty: %s, host: %s, command: %s, type: %d, task ID: %d"
 +
 +/* Write the accounting information to syslog. */
 +void accounting_to_syslog(char *user, char *tty, char *host, char *cmdmsg, int type, uint16_t task_id)
 +{
-+    trace(ACCOUNTING_LOG_FORMAT, user, tty, host, cmdmsg, type, task_id);
++    syslog(LOG_INFO, ACCOUNTING_LOG_FORMAT, user, tty, host, cmdmsg, type, task_id);
 +}
 \ No newline at end of file
 diff --git a/local_accounting.h b/local_accounting.h