cros_vm can handle kvm errors.

BUG=chromium:968349
TEST=local

Change-Id: I51a41bee08492482ee2ef0a8e98b6e6c7b61e943
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2470323
Auto-Submit: Achuith Bhandarkar <achuith@chromium.org>
Reviewed-by: Ben Pastene <bpastene@chromium.org>
Commit-Queue: Ben Pastene <bpastene@chromium.org>
Commit-Queue: Achuith Bhandarkar <achuith@chromium.org>
Cr-Commit-Position: refs/heads/master@{#817060}

build/chromeos/test_runner.py

@@ -959,15 +959,6 @@ def main():
       logging.error('The default DUT hostname of %s is unreachable.',
                     LAB_DUT_HOSTNAME)
       return 1
-  if args.use_vm:
-    if not os.path.exists('/dev/kvm'):
-      logging.error('/dev/kvm is missing. Is KVM installed on this machine?')
-      return 1
-    elif not os.access('/dev/kvm', os.W_OK):
-      logging.error(
-          '/dev/kvm is not writable as current user. Perhaps you should be '
-          'root?')
-      return 1
 
   args.cros_cache = os.path.abspath(args.cros_cache)
   return args.func(args, unknown_args)