whitespace
remove TODO comment

I also don't think it's correct anymore since Genome::Sys handles
cleanup for locks (as long as Perl isn't Killed).
catch create exceptions within get_or_create

get_or_create depends on retrying a get after create fails so if create
threw an exception then get_or_create would fail even though it didn't
necessarily need to.
can't propogate exception or something swallows it
fix failure in test due to incomplete cleanup on SR failure

Previously the test was passing due to a bug in Genome::SoftwareResult's
get_or_create that made the exception thrown here never make a second
get attempt.  Once that was fixed this started failing because the
creation cleanup left the object created (by UR::Object) behind.
get_or_create needs to catch expcetions from create