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-phosphor/common/recipes-phosphor/ipmi/phosphor-ipmi-fru/obmc-read-eeprom@.service b/meta-phosphor/common/recipes-phosphor/ipmi/phosphor-ipmi-fru/obmc-read-eeprom@.service
index ee83c7e..4bae65d 100644
--- a/meta-phosphor/common/recipes-phosphor/ipmi/phosphor-ipmi-fru/obmc-read-eeprom@.service
+++ b/meta-phosphor/common/recipes-phosphor/ipmi/phosphor-ipmi-fru/obmc-read-eeprom@.service
@@ -7,7 +7,8 @@
 Restart=no
 Type=oneshot
 EnvironmentFile={envfiledir}/obmc/eeproms/%I
-ExecStart={sbindir}/phosphor-read-eeprom --eeprom $SYSFS_PATH --fruid $FRUID
+ExecStart=/usr/bin/env phosphor-read-eeprom --eeprom $SYSFS_PATH --fruid $FRUID
+SyslogIdentifier=phosphor-read-eeprom
 
 [Install]
 WantedBy={SYSTEMD_DEFAULT_TARGET}