saio: Stop processes more forcefully in resetswift

We sometimes see probe test failures in the gate where `resetswift`
fails like

    umount: /mnt/sdb1: target is busy.

It seems to be because `swift-init all kill` is just a stop with a
status check after the fact. Add an orphan sweep afterwards to make
sure worker subprocesses got cleaned up, too.

Change-Id: I533b436a35e5c3deb7488e9961b55f2274c14751

doc/saio/bin/resetswift

@@ -3,6 +3,8 @@
 set -e
 
 swift-init all kill
+swift-orphans -a 0 -k KILL
+
 # Remove the following line if you did not set up rsyslog for individual logging:
 sudo find /var/log/swift -type f -exec rm -f {} \;
 if cut -d' ' -f2 /proc/mounts | grep -q /mnt/sdb1 ; then