install mask: filter /etc/xinetd.d

We don't use xinetd anywhere, so nuke the configs to save space.

BUG=None
TEST=CQ passes

Change-Id: I4a91b70451c2ae2d0c05d1a99e61c35f4558f7cf
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosutils/+/2695526
Tested-by: Mike Frysinger <vapier@chromium.org>
Auto-Submit: Mike Frysinger <vapier@chromium.org>
Commit-Queue: Allen Webb <allenwebb@google.com>
Reviewed-by: Allen Webb <allenwebb@google.com>
diff --git a/common.sh b/common.sh
index 31f75d2..b14bcde 100644
--- a/common.sh
+++ b/common.sh
@@ -403,6 +403,7 @@
   /etc/init.d
   /etc/runlevels
   /etc/selinux/intermediates
+  /etc/xinetd.d
   /firmware
   /lib/modules/*/vdso
   /lib/rc