usblp: Cosmetics

This is a small bunch of cosmetic fixes:
 - Timeout is not a write timeout anymore, rename
 - Condition in poll was confusingly backwards, invert and simplify
 - The comment log gave a wrong impression of version 0.13, terminate it.

Signed-off-by: Pete Zaitcev <zaitcev@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>