datapath-windows: Transactional error fix for flow dump.

My changes for trasacation error handling for not needed for dump commands.
Fixed the same.

Signed-off-by: Ankur Sharma <ankursharma@vmware.com>
Acked-by: Nithin Raju <nithin@vmware.com>
Acked-by: Eitan Eliahu <eliahue@vmware.com>
Signed-off-by: Ben Pfaff <blp@nicira.com>