Regressions: Fix the regress script when "all" is used.
Regressions: Fix the regress script when "all" is used.

When the "all" test is specified, the "tests" list should have two elements in
it, "quick" and "long", not a single element "quick,long". The later would be
appropriate as the default for one of the command line options which are split
at commas, but at that point "tests" should already be a list.

andrewfu0325/gem5-aladdin,andrewfu0325/gem5-aladdin,andrewfu0325/gem5-aladdin,andrewfu0325/gem5-aladdin,andrewfu0325/gem5-aladdin,andrewfu0325/gem5-aladdin,andrewfu0325/gem5-aladdin