build: consistent debhelper 10 support

Type: fix

debian/compat contents were set to 10, but debhelper build dependency,
which is the same thing, was set to only 9. Both are not needed,
debian/compat being deprecated, so use only the latter.
At compat level 10, dh-systemd is integrated directly into debhelper, so
build dependency not needed (And in Debian Bullseye dh-systemd
transitional package is completely removed).
See: https://manpages.debian.org/testing/debhelper/debhelper.7.en.html#COMPATIBILITY_LEVELS

Signed-off-by: Nick Brown <nickbroon@gmail.com>
Change-Id: I5809b739334076d7fa8389b076a97f1648726e6e

Makefile

@@ -63,7 +63,7 @@ endif
 # +libganglia1-dev if building the gmond plugin
 
 DEB_DEPENDS  = curl build-essential autoconf automake ccache
-DEB_DEPENDS += debhelper dkms git libtool libapr1-dev dh-systemd dh-python
+DEB_DEPENDS += debhelper dkms git libtool libapr1-dev dh-python
 DEB_DEPENDS += libconfuse-dev git-review exuberant-ctags cscope pkg-config
 DEB_DEPENDS += lcov chrpath autoconf libnuma-dev
 DEB_DEPENDS += python3-all python3-setuptools check

src/pkg/CMakeLists.txt

@@ -53,8 +53,6 @@ foreach(f copyright vpp.preinst vpp.postrm vpp.postinst vpp.service)
   )
 endforeach()
 
-file(WRITE ${VPP_BINARY_DIR}/debian/compat "10\n")
-
 add_custom_target(pkg-deb
   COMMENT "Building .deb packages..."
   WORKING_DIRECTORY ${VPP_BINARY_DIR}

src/pkg/debian/control.in

@@ -2,7 +2,7 @@ Source: vpp
 Section: net
 Priority: extra
 Maintainer: fd.io VPP Packaging Team <vpp-dev@fd.io>
-Build-Depends: debhelper (>= 9),
+Build-Depends: debhelper-compat (= 10),
                dh-systemd,
 	       dh-python,
 	       @VPP_DEB_BUILD_DEPENDS@