procd: update to git HEAD and add new script helpers

procd: update to git HEAD and add new script helpers

 e10de28 jail: cgroups-bpf: fix compile with musl 1.2
 f5d9b14 hotplug-dispatch: fix rare memory leaks in error paths

Add new init script helpers:
 procd_add_start_mount_trigger
 procd_add_reload_mount_trigger
 procd_get_mountpoints

Both trigger helpers expect a list of paths which are checked against
the mount targets configured in /etc/config/fstab and a trigger for all
mountpoints covered by the list of paths is setup.

procd_get_mountpoints is useful to find out if and which mountpoints
are covered by a list of paths.

Example:
  DATADIRS="/mnt/data/foo /mnt/data/bar /etc/foo/baz /var/lib/doe"

  start_service() {
    [ "$_BOOT" = "1" ] &&
      [ "$(procd_get_mountpoints $DATADIRS)" ] && return 0

    procd_open_instance
    # ...
    procd_close_instance
  }

  boot() {
    _BOOT=1 start
  }

  service_triggers() {
    procd_add_start_mount_trigger $DATADIRS
  }

Signed-off-by: Daniel Golle <daniel@makrotopia.org>