gerrit_stats: fix bugs in userexpand logic
gerrit_stats: fix bugs in userexpand logic

The limit has a typo, and once that's fixed we see we return not the
expanded addresses but a partial query which breaks the caller.

BUG=None
TEST=`gerrit_stats vapier` now works w/out fallback

Change-Id: Iff6e6742b25a4605c7fdcfa9c3c66a65853586e7
Reviewed-on: https://gerrit.chromium.org/gerrit/33783
Commit-Ready: Mike Frysinger <8f3f75c74bd5184edcfa6534cab3c13a00a2f794@chromium.org>
Reviewed-by: Mike Frysinger <8f3f75c74bd5184edcfa6534cab3c13a00a2f794@chromium.org>
Tested-by: Mike Frysinger <8f3f75c74bd5184edcfa6534cab3c13a00a2f794@chromium.org>

zhang0137/chromite,coreos/chromite,bpsinc-native/src_third_party_chromite,coreos/chromite,bpsinc-native/src_third_party_chromite,chadversary/chromiumos.chromite,zhang0137/chromite,coreos/chromite,bpsinc-native/src_third_party_chromite,zhang0137/chromite,chadversary/chromiumos.chromite