meta-ibm: Use proper path names in service files

Don't use /usr/bin/env, it's an antipattern.

Signed-off-by: Matt Spinler <spinler@us.ibm.com>
Change-Id: If388f5427bb2ca45718d0ca99452bf3f147861dd
diff --git a/meta-ibm/meta-romulus/recipes-phosphor/chassis/avsbus-control/avsbus-enable@.service b/meta-ibm/meta-romulus/recipes-phosphor/chassis/avsbus-control/avsbus-enable@.service
index b7fb41e..782590e 100644
--- a/meta-ibm/meta-romulus/recipes-phosphor/chassis/avsbus-control/avsbus-enable@.service
+++ b/meta-ibm/meta-romulus/recipes-phosphor/chassis/avsbus-control/avsbus-enable@.service
@@ -6,8 +6,7 @@
 ConditionPathExists=!/run/openbmc/chassis@%i-on
 
 [Service]
-ExecStart=/usr/bin/env avsbus-enable.sh
-SyslogIdentifier=avsbus-enable.sh
+ExecStart=/usr/bin/avsbus-enable.sh
 Type=oneshot
 RemainAfterExit=yes