fix parsing for `rustc -Z ls`
fix parsing for `rustc -Z ls`

The linked PR in the comment changed the output format, but never
bothered to change sccache to match the new output format.  So when we
stumbled across a case of the new output format, we panicked.

mozilla/sccache,mozilla/sccache,glandium/sccache,luser/sccache2,glandium/sccache,luser/sccache2,glandium/sccache,luser/sccache2,luser/sccache2,glandium/sccache,mozilla/sccache