systemd: use qualified path

Fix a documented anti-pattern:
https://github.com/openbmc/docs/blob/master/anti-patterns.md#use-of-usrbinenv-in-systemd-service-files

Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
Change-Id: I3ba0e5a53d711c7143cbabb3559e3bf9480af7e2
diff --git a/xyz.openbmc_project.Time.Manager.service b/xyz.openbmc_project.Time.Manager.service
index 76df596..369ff0e 100644
--- a/xyz.openbmc_project.Time.Manager.service
+++ b/xyz.openbmc_project.Time.Manager.service
@@ -5,8 +5,7 @@
 
 [Service]
 Restart=always
-ExecStart=/usr/bin/env phosphor-time-manager
-SyslogIdentifier=phosphor-time-manager
+ExecStart=/usr/bin/phosphor-time-manager
 Type=dbus
 BusName=xyz.openbmc_project.Time.Manager