vdev_id: Fix PHY sorting

One of our developers noticed a bug in vdev_id where we were incorrectly
sorting PHYs using alphabetical sorting (which usually works) instead
of natural sorting (-v).  For example:

	[port-0:0]# ls -d phy*
	phy-0:10  phy-0:11  phy-0:8  phy-0:9

	[port-0:0]# ls -vd phy*
	phy-0:8  phy-0:9  phy-0:10  phy-0:11

This fixes the issue.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes #12699

cmd/vdev_id/vdev_id

@@ -375,7 +375,7 @@ sas_handler() {
 		i=$((i + 1))
 	done
 
-	PHY=$(ls -d "$port_dir"/phy* 2>/dev/null | head -1 | awk -F: '{print $NF}')
+	PHY=$(ls -vd "$port_dir"/phy* 2>/dev/null | head -1 | awk -F: '{print $NF}')
 	if [ -z "$PHY" ] ; then
 		PHY=0
 	fi