Prints the depot_tools update notification to stderr instead of stdout.

Otherwise it's painful when using tricks like $(git cl upstream).

R=sky@chromium.org
BUG=
TEST=

Review URL: http://codereview.chromium.org/6727012

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@79084 0039d316-1c4b-4281-b951-d872f2087c98

update_depot_tools

@@ -51,7 +51,7 @@ then
   # work around a git-svn --quiet bug
   OUTPUT=`git svn rebase -q -q`
   if [[ ! "$OUTPUT" == *Current.branch* ]]; then
-    echo $OUTPUT
+    echo $OUTPUT 1>&2
   fi
   cd - > /dev/null
 fi
@@ -65,6 +65,6 @@ then
   svn -q up "$base_dir"
   AFTER_REVISION=$(get_svn_revision)
   if [[ "$BEFORE_REVISION" != "$AFTER_REVISION" ]]; then
-    echo "Depot Tools has been updated to revision $AFTER_REVISION."
+    echo "Depot Tools has been updated to revision $AFTER_REVISION." 1>&2
   fi
 fi