meta-openpower: fix shellcheck issues

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I35a9ffed937919467dec62a1fbff729f4a51366c
diff --git a/meta-openpower/recipes-phosphor/occ/openpower-occ-control/occ-active.sh b/meta-openpower/recipes-phosphor/occ/openpower-occ-control/occ-active.sh
index dc1f39b..bb9e482 100755
--- a/meta-openpower/recipes-phosphor/occ/openpower-occ-control/occ-active.sh
+++ b/meta-openpower/recipes-phosphor/occ/openpower-occ-control/occ-active.sh
@@ -1,15 +1,15 @@
 #!/bin/sh
 # set and unset occ active for all occ's in system
 
-if [ "$1" == "disable" ]; then
+if [ "$1" = "disable" ]; then
     value='false'
-elif [ "$1" == "enable" ]; then
+elif [ "$1" = "enable" ]; then
     value='true'
 else
     echo "Usage: occ-active.sh [argument]"
     echo "  enable  - set occ's to active state"
     echo "  disable - set occ's to inactive state"
-    exit -1
+    exit 1
 fi
 
 OCC_CONTROL_SERVICE="org.open_power.OCC.Control"