parser: fix --jobs so job scaling is applied correctly

job scaling allows the parser to resample the number of cpus available and increase the number of jobs that can be launched if cpu available increases.

Unfortunately job scaling was being applied even when a fixed number of jobs was specified. So --jobs=2

doesn't actually clamp the compile at 2 jobs.

Instead job scaling should only be applied when --jobs=auto or when jobs are set to a multiple of the cpus.

Signed-off-by: John Johansen john.johansen@canonical.com