repo-add: show better error when path to repo does not exist
Previously, the error message when trying to add to a repo where a
parent directory didn't exist was:
==> ERROR: Failed to acquire lockfile: /path/to/noexist/repo.tar.gz.lck
This sucks. Make an explicit check to ensure that the path to the repo
really does exist, and throw a meaningful error message when it can't be
found.
Dan: reuse an existing (translated) error message.
Signed-off-by: Dave Reisner <d@falconindy.com>
Signed-off-by: Dan McGee <dan@archlinux.org>