Coverity scan reports 1368529 and 1368528

*** CID 1368529:  Security best practices violations  (TOCTOU)

/test/recovery/random-abort.c: 355 in main()

349

350             absent = count = 0;

351             fatal = false;

352             for (i = 0; i < nth; ++i) {

353                     middle = 0;

354                     snprintf(fname, sizeof(fname), RECORDS_FILE, i);

>>>     CID 1368529:  Security best practices violations  (TOCTOU)

>>>     Calling function "fopen" that uses "fname" after a check function. This can cause a time-of-check, time-of-use race condition.

355                     if ((fp = fopen(fname, "r")) == NULL) {

356                             fprintf(stderr,

357                                 "Failed to open %s. i %" PRIu32 "\n", fname, i);

358                             testutil_die(errno, "fopen");

359                     }

360

*** CID 1368528:    (DEADCODE)

/bench/wtperf/wtperf.c: 2533 in main()

2527                    req_len += (user_cconfig != NULL ? strlen(user_cconfig) : 0);

2528                    req_len += (debug_cconfig != NULL ? strlen(debug_cconfig) : 0);

2529                    cc_buf = dmalloc(req_len);

2530

2531                    if (wtperf->async_config != NULL &&

2532                        strlen(wtperf->async_config)) {

>>>     CID 1368528:    (DEADCODE)

>>>     Execution cannot reach the expression "","" inside this statement: "pos += (uint32_t)snprintf(c...".

2533                            pos += (uint32_t)snprintf(

2534                                cc_buf + pos, req_len - pos, "%s%s",

2535                                append_comma ? "," : "", wtperf->async_config);

2536                            append_comma = true;

2537                    }

2538                    if (wtperf->compress_ext != NULL &&

/bench/wtperf/wtperf.c: 2585 in main()

2579                    req_len += (user_tconfig != NULL ? strlen(user_tconfig) : 0);

2580                    req_len += (debug_tconfig != NULL ? strlen(debug_tconfig) : 0);

2581                    tc_buf = dmalloc(req_len);

2582

2583                    if (wtperf->compress_table != NULL &&

2584                        strlen(wtperf->compress_table)) {

>>>     CID 1368528:    (DEADCODE)

>>>     Execution cannot reach the expression "","" inside this statement: "pos += (uint32_t)snprintf(t...".

2585                            pos += (uint32_t)snprintf(

2586                                tc_buf + pos, req_len - pos, "%s%s",

2587                                append_comma ? "," : "", wtperf->compress_table);

2588                            append_comma = true;

2589                    }

2590                    if (opts->index) {