systemd: cleanup removed services

Fixes QubesOS/qubes-issues#2192

debian/qubes-core-agent.postinst

@@ -128,6 +128,14 @@ case "${1}" in
             rm -f /lib/firmware/updates
         fi
 
+        # remove old symlinks
+        if [ -L /etc/systemd/system/sysinit.target.wants/qubes-random-seed.service ]; then
+            systemctl --no-reload disable qubes-random-seed.service >/dev/null
+        fi
+        if [ -L /etc/systemd/system/sysinit.target.wants/qubes-mount-home.service ]; then
+            systemctl --no-reload disable qubes-mount-home.service >/dev/null
+        fi
+
         if ! dpkg-statoverride --list /var/lib/qubes/dom0-updates >/dev/null 2>&1; then
             dpkg-statoverride --update --add user user 775 /var/lib/qubes/dom0-updates
         fi

rpm_spec/core-vm.spec

@@ -631,6 +631,14 @@ grep '^[[:space:]]*[^#;]' /lib/systemd/system-preset/75-qubes-vm.preset | while
     esac
 done
 
+# remove old symlinks
+if [ -L /etc/systemd/system/sysinit.target.wants/qubes-random-seed.service ]; then
+    systemctl --no-reload disable qubes-random-seed.service >/dev/null
+fi
+if [ -L /etc/systemd/system/sysinit.target.wants/qubes-mount-home.service ]; then
+    systemctl --no-reload disable qubes-mount-home.service >/dev/null
+fi
+
 /bin/systemctl daemon-reload
 
 exit 0