oracle: factor part of the initial setup for PTA queries

The check for len(argv)==0 now only applies to these modes.

Also, more consistent variable naming.

Change-Id: I9adb6bebc819eb43d54ddf63c42d952671ce9236
Reviewed-on: https://go-review.googlesource.com/8244
Reviewed-by: David Crawshaw <crawshaw@golang.org>
8 files changed