host-graceful-quiesce: call new target

This new target was introduced as a part of this updated design:
  https://gerrit.openbmc-project.xyz/c/openbmc/docs/+/52874

This allows the host firmware the opportunity to gracefully shutdown
when phosphor-logging detects it needs to Quiesce the host.

Signed-off-by: Andrew Geissler <geissonator@yahoo.com>
Change-Id: I6832fc947f4e0ce93717d2bbcfcb45cf3ebc6c38
diff --git a/log_manager.cpp b/log_manager.cpp
index c2a9b86..2aa3048 100644
--- a/log_manager.cpp
+++ b/log_manager.cpp
@@ -374,7 +374,7 @@
         "org.freedesktop.systemd1", "/org/freedesktop/systemd1",
         "org.freedesktop.systemd1.Manager", "StartUnit");
 
-    quiesce.append("obmc-host-quiesce@0.target");
+    quiesce.append("obmc-host-graceful-quiesce@0.target");
     quiesce.append("replace");
 
     this->busLog.call_noreply(quiesce);