may return a faster conclusion

[akostadinov]

Hello, I've run this interesting utility over an old disk that behaves strange. Like ~10MiB/s read speed and ~50MiB/s write speed. And some really bad badblocks behavior (read and validation errors). I ran it mostly for fun. It took some 20 hours to complete. I think diskscan can exit much earlier when major errors are found. Also a lot of error messages are not so clear. In any case, decided to put here my run logs in case author wish to check how program works.
Feel free to close issue. I just though such logs might be interesting if not anything else.

Especially errors like:

E: Error while attempting to overwrite uncorrectable data! ret=4096 errno=0: Success
E: Error when reading at offset 3222756864 size 65536 read 65536, errno=0: Success

-- Fedora 27, diskscan 1d1edcf

sdc.diskscan.output.log
sdc.diskscan.log