[Nbd] [patch] Use peername after free'd

[<ga...@je...>]

Attached is a patch that fixes a problem that peername is used after  
calling free. This is certainly bad, and causes problems in systems  
that use %s as the filename/connection mapping.   It seems to be that  
no connections should work w/o this fix, not sure how no one else has  
encountered this.

This problem seems to have been in the 2.9.x releases (certainly 2.9.2  
& 2.9.3)