Surprising use of basename in finish_log_named

[Erwan Velu <erwan@enovance.com>]

Hi Jens,

I had a input of the fio irc channel (yes some at getting into it 
sometimes :p), and he had a very interesting point.

If you specify a full path name for the iops_log, the file will stay 
into the current dir.
While looking at the code I found that finish_log_named() is performing 
the following:

     char file_name[256], *p;
     snprintf(file_name, sizeof(file_name), "%s_%s.log", prefix, postfix);
     p = basename(file_name);

Why do we basename the file_name ? What's the reason of shrinking the 
path this way ?

Note for the author: 256 is maybe too small for some ? :)))

Cheers,
Erwan