[PATCH] systemd: default system-sleep dir without pkg-config

[Mykola Kvach <xakep.amatop@xxxxxxxxx>]

From: Mykola Kvach <mykola_kvach@xxxxxxxx>

Using PKG_CHECK_VAR() to obtain SYSTEMD_SLEEP_DIR reintroduced a build-time
dependency on systemd-devel. This breaks --enable-systemd builds that only
need the initscripts.

Use the same defaulting scheme as other systemd paths: if SYSTEMD_SLEEP_DIR
isn't provided, set it to "$(prefix)/lib/systemd/system-sleep/".

Fixes: e54a6cd6a1f3 ("systemd: Add hooks to stop/start xen-watchdog on 
suspend/resume")
Reported-by: Marek Marczykowski-Górecki <marmarek@xxxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Mykola Kvach <mykola_kvach@xxxxxxxx>
---
Build in which the regression was detected:
https://gitlab.com/xen-project/people/marmarek/xen/-/jobs/10959608099
---
 m4/systemd.m4 | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/m4/systemd.m4 b/m4/systemd.m4
index c47a25ef93..ee684d3391 100644
--- a/m4/systemd.m4
+++ b/m4/systemd.m4
@@ -77,7 +77,7 @@ AC_DEFUN([AX_CHECK_SYSTEMD_LIBS], [
        ], [])
 
        AS_IF([test "x$SYSTEMD_SLEEP_DIR" = x], [
-           PKG_CHECK_VAR([SYSTEMD_SLEEP_DIR], [systemd], [systemdsleepdir])
+           SYSTEMD_SLEEP_DIR="\$(prefix)/lib/systemd/system-sleep/"
        ], [])
 
        AS_IF([test "x$SYSTEMD_SLEEP_DIR" = x], [
-- 
2.43.0