Coverity #1395811 Time of check time of use

37. Condition (__r = __wt_snprintf(fromfile, 4096UL /* sizeof (fromfile) */, "%s/%s", fromdir, dp->d_name)) != 0, taking true branch.

        testutil_check(__wt_snprintf(fromfile, sizeof(fromfile),

        "%s/%s", fromdir, dp->d_name));

 38. Condition (__r = __wt_snprintf(tofile, 4096UL /* sizeof (tofile) */, "%s/%s", todir, dp->d_name)) != 0, taking true branch.

        testutil_check(__wt_snprintf(tofile, sizeof(tofile),

        "%s/%s", todir, dp->d_name));  	

CID 1395811 (#1 of 1): Time of check time of use (TOCTOU)

39. fs_check_call: Calling function stat to perform check on fromfile.

40. Condition (__r = stat(fromfile, &sb)) != 0, taking true branch.

        testutil_check(stat(fromfile, &sb));