This is mostly a fix for in-tree build.

It removes errors on .d directories:

  grep: ./.gitlab-ci.d: Is a directory
  grep: ./scripts/qemu-guest-agent/fsfreeze-hook.d: Is a directory

and improves performance by only checking <ARCH>-linux-user directories.

Reported-by: BALATON Zoltan <balaton@eik.bme.hu>
Tested-by: BALATON Zoltan <balaton@eik.bme.hu>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20200323114116.163609-1-laurent@vivier.eu
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>