Fix activation helper which would return -ETIMEDOUT even if the last
retry attempt was successful.
Also change the semantics of the retries variable so that it actually
holds the number of retries (rather than tries).
Fixes: d2efbbd1 ("gnss: add driver for sirfstar-based receivers")
Cc: stable <email@example.com> # 4.19
Signed-off-by: Johan Hovold <firstname.lastname@example.org>