lib/sync: ignore download errors for as long as possible
Previously, the behavior was such that if a sync operation required
packages from multiple repos, a download error in the first repo would
cause a hard repo, ignoring the remainder of the repositories. Change
this behavior so that we do a better job of fetching as many packages as
possible before aborting the transaction.
There's a little bit of refactoring mixed in here to get rid of some
useless variables. Since we now depend heavily on the value of
handle->pm_errno being accurate the determine the function's return
value, we clear it when the transaction state is set.
Fixes FS#25532.
Signed-off-by: Dave Reisner <dreisner@archlinux.org>
Signed-off-by: Dan McGee <dan@archlinux.org>