systemd: enable create-log-dirs

By default, create-log-dirs  is enabled in systemd, and a link
/var/log/README will be created, point to {{DOC_DIR}}/README.logs, but,
for oe, there are two problems here, firstly, DOC_DIR is packaged in
another package systemd-doc, so /var/log/README is a dead link when
systemd-doc is not installed, secondly, even systemd-doc is installed,
when volatile log is used, DOC_DIR is a wrong relateive path, Refer [1].

So in commit [2], we disable create-log-dirs for above issue. with this
change, /var/log/journal is not created, and /run/log is used, this
makes systemd log always non persistent, refer [3][4]. if user need
persistent log, they need to disable volatile log, and also  change
journald.conf, make "Storage" to "persistent". This is a behavoir change.
Previously, to make systemd log persistent, user only need to disable
volatile log.

This commit reenable create-log-dirs to revert the behavior change, and
since README is not very userful, just remove it.

[ YOCTO #15678 ]

[1] https://github.com/systemd/systemd/blob/main/tmpfiles.d/legacy.conf.in#L16
[2] https://git.openembedded.org/openembedded-core/commit/?id=18d46e11d85da1f6feaba5a135931e43060024d6
[3] https://github.com/systemd/systemd/blob/main/src/journal/meson.build#L189
[4] https://www.freedesktop.org/software/systemd/man/journald.conf.html
[5] https://bugzilla.yoctoproject.org/show_bug.cgi?id=15678

(From OE-Core rev: f82d9c997ba8cc23b472d44a43489c597bf452af)

Signed-off-by: Changqing Li <changqing.li@windriver.com>
Signed-off-by: Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-core/systemd/systemd_257.1.bb

@@ -245,7 +245,6 @@ EXTRA_OEMESON += "-Dnobody-user=nobody \
                   -Dsystem-uid-max=999 \
                   -Dsystem-alloc-gid-min=101 \
                   -Dsystem-gid-max=999 \
-                  -Dcreate-log-dirs=false \
                   ${@bb.utils.contains('DISTRO_FEATURES', 'zeroconf', '-Ddefault-mdns=no -Ddefault-llmnr=no', '', d)} \
                   "
 
@@ -394,6 +393,10 @@ do_install() {
 		# Actively disable Predictable Network Interface Names
 		sed -i 's/^NamePolicy=.*/NamePolicy=/;s/^AlternativeNamesPolicy=.*/AlternativeNamesPolicy=/' ${D}${nonarch_libdir}/systemd/network/99-default.link
 	fi
+
+	if [ -e ${D}${nonarch_libdir}/tmpfiles.d/legacy.conf ];then
+		sed -i -e '/^L \/var\/log\/README/d' ${D}${nonarch_libdir}/tmpfiles.d/legacy.conf
+	fi
 }
 
 python populate_packages:prepend (){