Add ShellCheck's --enable=all inside cmd/

The only exception is `cmd/vdev_id/vdev_id` which might be a subject of
refactoring (see #12084)

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Signed-off-by: szubersk <szuberskidamian@gmail.com>
Closes #12912

cmd/zpool/zpool.d/ses

@@ -24,6 +24,7 @@ else
 fi
 
 for i in $scripts ; do
+	# shellcheck disable=SC2154
 	if [ -z "$VDEV_ENC_SYSFS_PATH" ] ; then
 		echo "$i="
 		continue
@@ -52,7 +53,9 @@ for i in $scripts ; do
 	locate_led)
 		val=$(cat "$VDEV_ENC_SYSFS_PATH/locate" 2>/dev/null)
 		;;
+	*)
+		val=invalid
+		;;
 	esac
 	echo "$i=$val"
 done
-