CI: upgrade-compat: fix 2x chroot still active msg (MR 12)

Use -q with the last pmbootstrap command to avoid printing the "chroot
still active" and "done" lines twice. Remove the empty line at the end
of the file while at it.

(009828) [23:19:38] NOTE: chroot is still active (use 'pmbootstrap shutdown' as necessary)
(009828) [23:19:38] DONE!
(009088) [23:19:38] NOTE: chroot is still active (use 'pmbootstrap shutdown' as necessary)
(009088) [23:19:38] DONE!

.ci/upgrade-compat.sh

@@ -41,5 +41,4 @@ pmbootstrap --details-to-stdout install --no-image --password test
 
 # Execute upgrade in rootfs
 cp upgrade.sh "$WORK"/chroot_rootfs_"$DEVICE"/tmp/upgrade.sh
-yes | pmbootstrap chroot -r -- /tmp/upgrade.sh "$CHANNEL_NEW"
-
+yes | pmbootstrap -q chroot -r -- /tmp/upgrade.sh "$CHANNEL_NEW"