update_engine: update cros lint usage

Drop gnlint as it's in cros lint now.  Use the new --commit option.

BUG=None
TEST=CQ passes

Change-Id: Ib7d5330724ea1386f838376286fb37a182b16995
Reviewed-on: https://chromium-review.googlesource.com/c/aosp/platform/system/update_engine/+/4394898
Commit-Queue: Mike Frysinger <vapier@chromium.org>
Reviewed-by: Jae Hoon Kim <kimjae@chromium.org>
Tested-by: Mike Frysinger <vapier@chromium.org>
diff --git a/PRESUBMIT.cfg b/PRESUBMIT.cfg
index 42156b3..304855f 100644
--- a/PRESUBMIT.cfg
+++ b/PRESUBMIT.cfg
@@ -1,6 +1,5 @@
 [Hook Scripts]
-cros lint = cros lint ${PRESUBMIT_FILES}
-gnlint = ../../../platform2/common-mk/gnlint.py ${PRESUBMIT_FILES}
+cros lint = cros lint --commit ${PRESUBMIT_COMMIT} ${PRESUBMIT_FILES}
 
 [Hook Overrides]
 clang_format_check: true