containerd: use service file from source tree

We no longer need to support both the docker and opencontainer
variants, so we can just grab the service file from the source tree.

Signed-off-by: Bruce Ashfield <bruce.ashfield@gmail.com>

recipes-containers/containerd/containerd-opencontainers_git.bb

@@ -9,7 +9,6 @@ SRCREV = "33d90b72d1e44987118ac111d4f7a108d412099b"
 SRC_URI = "git://github.com/containerd/containerd;branch=release/1.4 \
            file://0001-build-use-oe-provided-GO-and-flags.patch \
            file://0001-Add-build-option-GODEBUG-1.patch \
-           file://containerd.service \
           "
 
 # Apache-2.0 for containerd
@@ -105,7 +104,7 @@ do_install() {
 
 	if ${@bb.utils.contains('DISTRO_FEATURES','systemd','true','false',d)}; then
 		install -d ${D}${systemd_unitdir}/system
-		install -m 644 ${WORKDIR}/containerd.service ${D}/${systemd_unitdir}/system
+		install -m 644 ${S}/src/import/containerd.service ${D}/${systemd_unitdir}/system
 	        # adjust from /usr/local/bin to /usr/bin/
 		sed -e "s:/usr/local/bin/containerd:${bindir}/containerd:g" -i ${D}/${systemd_unitdir}/system/containerd.service
 	fi

recipes-containers/containerd/files/containerd.service

@@ -1,11 +0,0 @@
-[Unit]
-Description=containerd
-Documentation=https://containerd.tools
-After=network.target
-
-[Service]
-ExecStart=/usr/local/bin/containerd
-Delegate=yes
-
-[Install]
-WantedBy=multi-user.target