agent: Pep8 fixes

* CredServer
* GuestAgentLinux2
* VirtIoChannel
* WinFile
* version
* setup.py - FP on py2exe import
* OVirtGuestAgent
* OVirtAgentLogic
* ovirt-guest-agent
* LockActiveSession
* GuestAgentWin32

Change-Id: I74c33ed2ef2e5c33b9d25cb8b38e4201d67a957b
Signed-off-by: Vinzenz Feenstra <vfeenstr@redhat.com>