cros_build_lib.run: clean up error_code_ok->check migration

BUG=chromium:1006587
TEST=`./run_tests` passes

Change-Id: Ie416c5f7b16314a34a3a53f503469b3cc93fb9e2
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/chromite/+/1965957
Commit-Queue: Mike Frysinger <vapier@chromium.org>
Tested-by: Mike Frysinger <vapier@chromium.org>
Reviewed-by: Chris McDonald <cjmcdonald@chromium.org>
diff --git a/scripts/loman.py b/scripts/loman.py
index 861bbef..a1b8893 100644
--- a/scripts/loman.py
+++ b/scripts/loman.py
@@ -83,7 +83,7 @@
   git_config = options.git_config
 
   cmd = ['config', '-f', git_config, '--get', 'manifest.groups']
-  enabled_groups = git.RunGit('.', cmd, error_code_ok=True).output.split(',')
+  enabled_groups = git.RunGit('.', cmd, check=False).output.split(',')
 
   # Note that ordering actually matters, thus why the following code
   # is written this way.