udev alsa restore restore rules are broken

To reproduce:

1. Run the following command: udevadm test --action=add /class/sound/controlC0 2>/dev/null | grep alsactl

Expected output:

run: '/usr/sbin/alsactl restore 0'

Actual output:

run: '/usr/sbin/alsactl restore '

Note the missing '0' - this causes alsactl to restore the levels on all cards instead of the one that was just plugged in. The rules file looks like this:

TEST!="/var/lib/alsa/state-daemon.conf", RUN+="/usr/sbin/alsactl restore $attr{number}"

This has not changed since raring (where this stuff works correctly). Under saucy the $attr{number} macro expands to empty string.

udevadm info --query=all --path=/class/sound/controlC0 --attribute-walk outputs exactly the same attributes on both saucy and raring.

ProblemType: Bug
DistroRelease: Ubuntu 13.10
Package: alsa-utils 1.0.27.1-1ubuntu1 [modified: lib/udev/rules.d/90-alsa-restore.rules usr/sbin/alsactl]
Uname: Linux 3.11.0-031100-generic x86_64
NonfreeKernelModules: nvidia
ApportVersion: 2.12.5-0ubuntu2.2
Architecture: amd64
Date: Sun Jan 12 13:06:47 2014
InstallationDate: Installed on 2013-08-27 (137 days ago)
InstallationMedia: Xubuntu 13.10 "Saucy Salamander" - Alpha amd64 (20130827)
MarkForUpload: True
SourcePackage: alsa-utils
UpgradeStatus: No upgrade log present (probably fresh install)