17159cd70f
breaks too many situations, including MAKEOBJDIR with a :C,foo,bar,
transform in many cases. It's ambiguous and unreliable, as the comment
above that code always indicated. In order to have reliable objdirs, they
need to work the same way Every Time.
(Note that taking this out is not a performance hit; we were already doing
the getcwd() call first. So the getenv("PWD") didn't increase performance.)