Remove 'file_size' check from tests. The docstring indicates this par…

…ameter is to be passed to the callback, and there's no reason to think this parameter is relevant in affecting whether a useful stat object has been passed (especially when the 'confirm' parameter is explicitly supplied for that decision. This fixes paramiko#142.

paramiko/sftp_client.py

@@ -575,7 +575,7 @@ def putfo(self, fl, remotepath, file_size=0, callback=None, confirm=True):
                     break
         finally:
             fr.close()
-        if confirm and file_size:
+        if confirm:
             s = self.stat(remotepath)
             if s.st_size != size:
                 raise IOError('size mismatch in put!  %d != %d' % (s.st_size, size))