FIX for smbtar zero length files...

[James Delahanty]

We've recently run into a headache when backing up NT servers from our
Linux server.  A run with verbose output would look like this:

Normal Stuff
...
Error reading file \1002\alignment\redelltest.dgn. Got 0 bytes
Didn't get entire file. size=12288, nread=0
     12288 (  193.5 kb/s) \1002\alignment\redelltest.dgn
...
Error reading file \1002\alignment\_a_blank.dgn. Got 0 bytes
Didn't get entire file. size=12288, nread=0
     12288 (  279.1 kb/s) \1002\alignment\_a_blank.dgn

And, as