Fix early access of cleartool when loading SCMTools.
Fix early access of cleartool when loading SCMTools.

There was one instance where we were still trying to run cleartool
during initialization, even when it's not being used. This could result
in ugly errors being printed to the console.

Testing Done:
Posted a change and no longer saw an ugly traceback.

Reviewed at https://reviews.reviewboard.org/r/11826/

reviewboard/rbtools,reviewboard/rbtools,reviewboard/rbtools