systemd: resolve executable path if it is relative

Backport a patch to fix the below systemd-analyze issue:
 # systemd-analyze --man=false verify /lib/systemd/system/initrd-cleanup.service
 initrd-cleanup.service: Command systemctl is not executable: No such file or directory

 # which systemctl
 /bin/systemctl

 # cat /lib/systemd/system/initrd-cleanup.service
 [snip]
 [Unit]
 Description=Cleaning Up and Shutting Down Daemons
 DefaultDependencies=no
 AssertPathExists=/etc/initrd-release
 OnFailure=emergency.target
 OnFailureJobMode=replace-irreversibly
 After=initrd-root-fs.target initrd-fs.target initrd.target

 [Service]
 Type=oneshot
 ExecStart=systemctl --no-block isolate initrd-switch-root.target

(From OE-Core rev: 2e0259931f71701147039bb8e60251892f67dbcd)

Signed-off-by: Mingli Yu <mingli.yu@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-core/systemd/systemd/0001-analyze-resolve-executable-path-if-it-is-relative.patch

@@ -0,0 +1,39 @@
+From b9b7a8e3825f0433e120f7a6d7d5d635a839cab9 Mon Sep 17 00:00:00 2001
+From: Mingli Yu <mingli.yu@windriver.com>
+Date: Thu, 21 Jan 2021 06:19:44 +0000
+Subject: [PATCH] analyze: resolve executable path if it is relative
+
+Upstream-Status: Backport [https://github.com/systemd/systemd/commit/f1fb046a985521f7d4a662f02546686ff20b7e5d]
+
+Signed-off-by: Mingli Yu <mingli.yu@windriver.com>
+---
+ src/analyze/analyze-verify.c | 7 +++++--
+ 1 file changed, 5 insertions(+), 2 deletions(-)
+
+diff --git a/src/analyze/analyze-verify.c b/src/analyze/analyze-verify.c
+index a9c89173bf..969523df18 100644
+--- a/src/analyze/analyze-verify.c
++++ b/src/analyze/analyze-verify.c
+@@ -115,14 +115,17 @@ static int verify_socket(Unit *u) {
+ }
+ 
+ int verify_executable(Unit *u, const ExecCommand *exec) {
++        int r;
++
+         if (!exec)
+                 return 0;
+ 
+         if (exec->flags & EXEC_COMMAND_IGNORE_FAILURE)
+                 return 0;
+ 
+-        if (access(exec->path, X_OK) < 0)
+-                return log_unit_error_errno(u, errno, "Command %s is not executable: %m", exec->path);
++        r = find_executable_full(exec->path, false, NULL);
++        if (r < 0)
++                return log_unit_error_errno(u, r, "Command %s is not executable: %m", exec->path);
+ 
+         return 0;
+ }
+-- 
+2.26.2
+

meta/recipes-core/systemd/systemd_247.2.bb

@@ -24,6 +24,7 @@ SRC_URI += "file://touchscreen.rules \
            file://0001-systemd.pc.in-use-ROOTPREFIX-without-suffixed-slash.patch \
            file://0001-logind-Restore-chvt-as-non-root-user-without-polkit.patch \
            file://0027-proc-dont-trigger-mount-error-with-invalid-options-o.patch \
+           file://0001-analyze-resolve-executable-path-if-it-is-relative.patch \
            "
 
 # patches needed by musl