system/skeleton: provide run/lock directory

We changed the skeletons in bf01e51f3c, so that var/lock
points to run/lock. This resulted in build failures as
some packages want to work with these paths.

-   Create run/lock, the run directory will be purged
    later anyway (since 5e78e7e97d).
-   for init == systemd, create the var/lock symlink early
    to prevent packages creating this path as directory.

Fixes:
http://autobuild.buildroot.net/results/3ee/3ee8f9ee55e51af38e9dbe7b9840c9589d88a30f

Signed-off-by: Norbert Lange <nolange79@gmail.com>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>

package/skeleton-init-systemd/skeleton-init-systemd.mk

@@ -62,6 +62,8 @@ define SKELETON_INIT_SYSTEMD_INSTALL_TARGET_CMDS
 	mkdir -p $(TARGET_DIR)/srv
 	mkdir -p $(TARGET_DIR)/var
 	ln -s ../run $(TARGET_DIR)/var/run
+	# prevent install scripts to create var/lock as directory
+	ln -s ../run/lock $(TARGET_DIR)/var/lock
 	install -D -m644 $(SKELETON_INIT_SYSTEMD_PKGDIR)/legacy.conf $(TARGET_DIR)/usr/lib/tmpfiles.d/legacy.conf
 	$(SKELETON_INIT_SYSTEMD_ROOT_RO_OR_RW)
 endef