Add "settled" and "finished" hooks to force dracut event loop to fire

The only hooks guaranteed to run in the dracut event loop are "finished"
hooks. If none are installed (or they all indicate success up front), no
other "initqueue" or "settled" hooks will ever run. This includes, e.g.,
console initialization.

Rather than force console initialization in zfsbootmenu-preinit.sh,
let's add a initqueue/settled and initqueue/finished hooks that,
respectively, touch and watch for a file. This will force at least one
iteration of the entire event loop (except for "timeout" hooks, which
may still be short-circuited). If we want, we can make the settled hook
more sophisticated and use it to stand up the necessary pre-requisites.

90zfsbootmenu/module-setup.sh

@@ -151,6 +151,9 @@ install() {
   inst_simple "${moddir}/zkexec.sh" "/bin/zkexec" || _ret=$?
   inst_hook cmdline 95 "${moddir}/zfsbootmenu-parse-commandline.sh" || _ret=$?
   inst_hook pre-mount 90 "${moddir}/zfsbootmenu-preinit.sh" || _ret=$?
+  # Add hooks to force the dracut event loop to fire at least once
+  inst_hook initqueue/settled 99 "${moddir}/zfsbootmenu-ready-set.sh" || _ret=$?
+  inst_hook initqueue/finished 99 "${moddir}/zfsbootmenu-ready-chk.sh" || _ret=$?
 
   # Install "early setup" hooks
   # shellcheck disable=SC2154

90zfsbootmenu/zfsbootmenu-preinit.sh

@@ -43,11 +43,5 @@ getcmdline | sed -e 's/^[ \t]*//' > "${BASE}/zbm.cmdline"
 # Set a non-empty hostname so we show up in zpool history correctly
 echo "ZFSBootMenu" > /proc/sys/kernel/hostname
 
-# try to set console options for display and interaction
-# this is sometimes run as an initqueue hook, but cannot be guaranteed
-#shellcheck disable=SC2154
-[ -x /lib/udev/console_init ] && [ -c "${control_term}" ] \
-  && /lib/udev/console_init "${control_term##*/}" >/dev/null 2>&1
-
 # https://busybox.net/FAQ.html#job_control
 exec setsid bash -c "exec /libexec/zfsbootmenu-init <${control_term} >${control_term} 2>&1"

90zfsbootmenu/zfsbootmenu-ready-chk.sh

@@ -0,0 +1,2 @@
+#!/bin/bash
+test -f /zfsbootmenu/ready

90zfsbootmenu/zfsbootmenu-ready-set.sh

@@ -0,0 +1,3 @@
+#!/bin/bash
+mkdir -p /zfsbootmenu
+: > /zfsbootmenu/ready