Remove device paths from SubRun

The ability to have device paths was removed a while ago.
Remove the code for device paths.

Change-Id: I09418eaa464b040c7bb13eac2e167997363e49d1
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/255530
Reviewed-by: Ben Wagner <bungeman@google.com>
Commit-Queue: Herb Derby <herb@google.com>
3 files changed