mantle: detect when dumping to the virtio port failed

This will help warn the user that the normal passing of information
didn't work right so we can investigate it further. We were seeing
this race condition in coreos/fedora-coreos-tracker#2019

Author: dustymabe

mantle/kola/tests/ignition/qemufailure.go

@@ -133,7 +133,17 @@ func verifyError(builder *platform.QemuBuilder, searchPattern string) error {
 		if err := inst.Kill(); err != nil {
 			return errors.Wrapf(err, "failed to kill the vm instance")
 		}
-		return errors.Wrapf(ctx.Err(), "timed out waiting for initramfs error")
+		// If somehow the journal dumping failed let's flag that. We
+		// just ignore errors here. This effort is only trying to help
+		// be more informative about why things failed. This "string"
+		// we are searching for comes from ignition-virtio-dump-journal
+		searchPattern = "Didn't find virtio port /dev/virtio-ports/com.coreos.ignition.journal"
+		found, _ := fileContainsPattern(builder.ConsoleFile, searchPattern)
+		if found {
+			return errors.Wrapf(ctx.Err(), "Journal dumping during emergency.target failed")
+		} else {
+			return errors.Wrapf(ctx.Err(), "timed out waiting for initramfs error")
+		}
 	case err := <-errchan:
 		if err != nil {
 			return err