[scudo] Make logging more consistent

Summary:
A few changes related to logging:
- prepend `Scudo` to the error messages so that users can identify that we
  reported an error;
- replace a couple of `Report` calls in the RSS check code with
  `dieWithMessage`/`Print`, mark a condition as `UNLIKELY` in the process;
- change some messages so that they all look more or less the same. This
  includes the `CHECK` message;
- adapt a couple of tests with the new strings.

A couple of side notes: this results in a few 1-line-blocks, for which I left
brackets. There doesn't seem to be any style guide for that, I can remove them
if need be. I didn't use `SanitizerToolName` in the strings, but directly
`Scudo` because we are the only users, I could change that too.

Reviewers: alekseyshl, flowerhack

Reviewed By: alekseyshl

Subscribers: mgorny, delcypher, llvm-commits, #sanitizers

Differential Revision: https://reviews.llvm.org/D44171

llvm-svn: 326901

0 files changed, 0 insertions, 0 deletions