This reverts commit 
b052ce4c840e ("kbuild: fix false positive -dirty
tag caused by make-kpkg").
If I understand correctly, this problem occurred in very old versions
of make-kpkg. When I tried a newer version, make-kpkg did not touch
scripts/package/Makefile.
Anyway, Debian uses 'make deb-pkg' instead of make-kpkg these days.
Debian handbook [1] mentions it as "the good old days":
 "CULTURE The good old days of kernel-package
  Before the Linux build system gained the ability to build proper
  Debian packages, the recommended way to build such packages was to
  use make-kpkg from the kernel-package package."
[1]: https://debian-handbook.info/browse/stable/sect.kernel-compilation.html
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Nico Schottelius <nico-linuxsetlocalversion@schottelius.org>
                if {
                        git --no-optional-locks status -uno --porcelain 2>/dev/null ||
                        git diff-index --name-only HEAD
-               } | grep -qvE '^(.. )?scripts/package'; then
+               } | read dummy; then
                        printf '%s' -dirty
                fi
        fi