Enable BMC patching from the /usr/local path

This commit enables patches from the /usr/local path by replacing
absolute paths to /usr/sbin or /usr/bin in every service file with
"/usr/bin/env ". Additionally, SyslogIdentifier is added to each
file to ensure that journal entries are still distinct.

In two cases, service files also had to change due to references
to ${{PATH}}, which doesn't work with /usr/bin/env. These
references - and the corresponding definitions - were changed to
${{DEVPATH}}.

Resolves openbmc/openbmc#2149

Change-Id: I12c5c6e5101eef6820b985a563313836250ff2c7
Signed-off-by: Michael Tritz <mtritz@us.ibm.com>
diff --git a/meta-openbmc-machines/meta-openpower/common/recipes-phosphor/debug/openpower-debug-collector/openpower-debug-collector-watchdog@.service b/meta-openbmc-machines/meta-openpower/common/recipes-phosphor/debug/openpower-debug-collector/openpower-debug-collector-watchdog@.service
index 0bb2221..6fc3fec 100644
--- a/meta-openbmc-machines/meta-openpower/common/recipes-phosphor/debug/openpower-debug-collector/openpower-debug-collector-watchdog@.service
+++ b/meta-openbmc-machines/meta-openpower/common/recipes-phosphor/debug/openpower-debug-collector/openpower-debug-collector-watchdog@.service
@@ -3,6 +3,7 @@
 Before=obmc-host-quiesce@%i.target
 
 [Service]
-ExecStart={sbindir}/watchdog_timeout
+ExecStart=/usr/bin/env watchdog_timeout
+SyslogIdentifier=watchdog_timeout
 Type=oneshot
 Restart=no