Remove duplicate free in acct.c for *pak

Summary:
- Remove duplicate free causing stack trace
- tac_plus.c was always free'ing pak - No need to do it in accounting
  function

Reviewers: dgadling

Test Plan:
- Rerun on devserver + test in prod

Task ID: #4193634

tacacs+-F4.0.4.19/acct.c

@@ -59,8 +59,6 @@ accounting(u_char *pak)
     }
 
     account(pak);
-
-    free(pak);
 }
 
 static void