volatile-binds: correct some errors reported by systemd

systemd-tmpfiles-setup will fail at boot, so we suppress
the default versions of etc.conf and home.conf.

We also make sure that /var/{cache,spool} and /srv are writeable
if they exist.

(From OE-Core rev: a7c6129a7c9c0c7e1b729e16a60b2ca704af3f97)

Signed-off-by: Joe Slater <jslater@windriver.com>
Signed-off-by: Armin Kuster <akuster808@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-core/volatile-binds/volatile-binds.bb

@@ -17,6 +17,9 @@ REQUIRED_DISTRO_FEATURES = "systemd"
 
 VOLATILE_BINDS ?= "\
     /var/volatile/lib /var/lib\n\
+    /var/volatile/cache /var/cache\n\
+    /var/volatile/spool /var/spool\n\
+    /var/volatile/srv /srv\n\
 "
 VOLATILE_BINDS[type] = "list"
 VOLATILE_BINDS[separator] = "\n"
@@ -67,5 +70,11 @@ do_install () {
     for service in ${SYSTEMD_SERVICE_volatile-binds}; do
         install -m 0644 $service ${D}${systemd_unitdir}/system/
     done
+
+    # Suppress attempts to process some tmpfiles that are not temporary.
+    #
+    install -d ${D}${sysconfdir}/tmpfiles.d ${D}/var/cache
+    ln -s /dev/null ${D}${sysconfdir}/tmpfiles.d/etc.conf
+    ln -s /dev/null ${D}${sysconfdir}/tmpfiles.d/home.conf
 }
 do_install[dirs] = "${WORKDIR}"