Don't print "Updating depot_tools"

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Bug: 1418413
Change-Id: I37f92933dd6c5b40229cd8472551c0d1a3b5e962
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/5123952
Reviewed-by: Will Harris <wfh@chromium.org>
Auto-Submit: Gavin Mak <gavinmak@google.com>
Commit-Queue: Will Harris <wfh@chromium.org>

update_depot_tools

@@ -120,7 +120,6 @@ function update_git_repo {
 
 # Update git checkouts.
 if [ "X$DEPOT_TOOLS_UPDATE" != "X0" ]; then
-  echo "Updating depot_tools..." 1>&2
   if [ -e "$base_dir/.git" ]; then
     cd "$base_dir"
     update_git_repo