FYI: Fix for fish upload

[Pavel Roskin <proski gnu org>]

Hello!

I noticed that the upload on the fish filesystem stopped working some time
ago.  It turned out that the call to command() in file_store() used
variable of type off_t (64-bit if large files are enabled) with the "%d"
format.

Declaring command() with gcc __attribute__ would make this problem 
visible much earlier.  I'm going to add __attribute__ whenever possible.

I'm afraid that the fish upload is broken in mc-4.5.55 on alpha and other
64-bit architectures even in the default configuration.  Now it should be 
fixed.

For now, the maximum file size for fish uploads on 32-bit systems is
limited to 16 terabytes.  Should be enough for everybody.  Even that may 
be too much if "dd" on the other end is 32-bit (i.e. is limited to 4 
gigabytes).

The patch has been committed and the snapshot has been uploaded.

-- 
Regards,
Pavel Roskin