CHROMIUM: info: do not note up-to-date indexes

The info indexes are usually up-to-date, and devs need not care.
Kill off another useless log entry to tighten up output.

BUG=chromium:996480
TEST=`emerge libaio` doesn't spam this at the end

Change-Id: Iacc759b5beb4830ea23c3f070de7f1b12be26af7
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/portage_tool/+/1961316
Reviewed-by: Chris McDonald <cjmcdonald@chromium.org>
Tested-by: Mike Frysinger <vapier@chromium.org>
Commit-Queue: Mike Frysinger <vapier@chromium.org>
diff --git a/lib/portage/util/_info_files.py b/lib/portage/util/_info_files.py
index fabf74b..b4181d7 100644
--- a/lib/portage/util/_info_files.py
+++ b/lib/portage/util/_info_files.py
@@ -28,6 +28,8 @@
 							regen_infodirs.append(inforoot)
 
 		if not regen_infodirs:
+			# CrOS: We don't care about this noise.
+			return
 			portage.util.writemsg_stdout("\n")
 			if portage.util.noiselimit >= 0:
 				out.einfo("GNU info directory index is up-to-date.")