rust_uprev: accept -r* in virtual/rust version numbers

The ebuilds in virtual/rust can have patch (-r123) version numbers,
which currently cause rust_uprev to fail. This CL updates rust_uprev
to handle those.

BUG=chromium:1159066
TEST=python3 ./rust_tools/rust_uprev_test.py

Change-Id: I76ccaf553ea192db57e17ff3df9b02eee4105010
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/toolchain-utils/+/2593514
Commit-Queue: Bob Haarman <inglorion@chromium.org>
Tested-by: Bob Haarman <inglorion@chromium.org>
Reviewed-by: George Burgess <gbiv@chromium.org>
Reviewed-by: Tiancong Wang <tcwang@google.com>
2 files changed