findmissing: initdb_chromeos: Reduce logging noise

When checking out and updating a branch we don't need to see git output
in the log unless there is an error. The branch name in question is
already logged. Silence git to reduce logging noise.

BUG=None
TEST=Run on GCE

Change-Id: Ib5c9ec2708262fbf119945d100778facd36c1ba6
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/dev-util/+/2207525
Reviewed-by: Curtis Malainey <cujomalainey@chromium.org>
Commit-Queue: Guenter Roeck <groeck@chromium.org>
Tested-by: Guenter Roeck <groeck@chromium.org>
diff --git a/contrib/findmissing/initdb_chromeos.py b/contrib/findmissing/initdb_chromeos.py
index fbecabc..0b3cc0d 100755
--- a/contrib/findmissing/initdb_chromeos.py
+++ b/contrib/findmissing/initdb_chromeos.py
@@ -28,8 +28,8 @@
         entire commit log on each run.
     Skip commit if it is contained in the linux stable db, add to linux_chrome
     """
-    subprocess.run(['git', 'checkout', common.chromeos_branch(branch)], check=True)
-    subprocess.run(['git', 'pull'], check=True)
+    subprocess.run(['git', 'checkout', '-q', common.chromeos_branch(branch)], check=True)
+    subprocess.run(['git', 'pull', '-q'], check=True)
 
     cmd = ['git', 'log', '--abbrev=12', '--oneline', '--reverse', '%s..' % start]
     commits = subprocess.check_output(cmd, encoding='utf-8', errors='ignore')