crash-reporter: fix pstore detection The current Enable logic looks for an existing crash rather than the crash dir itself, so when we boot up clean we get a warning that we do not support kernel crashes. BUG=chromium:417350 TEST=`FEATURES=test emerge-link crash-reporter` passes TEST=`cbuildbot amd64-generic-full` passes TEST=booted VM and checked syslogs Change-Id: I076a37889ea10ed30ae522eba007619b001ec787 Reviewed-on: https://chromium-review.googlesource.com/219751 Tested-by: Mike Frysinger <[email protected]> Reviewed-by: Luigi Semenzato <[email protected]> Commit-Queue: Mike Frysinger <[email protected]>