Use the absolute path to modprobe

This is necessary on Fedora, according to Rolf Fokkens.
Install the initramfs hook in /usr/share not /etc

This location will trigger an initramfs rebuild on package install.
Merge branch 'master' into debian

* master:
  Install the initramfs hook in /usr/share not /etc
  Use the absolute path to modprobe
initramfs: Move hook to /usr/share, trigger a rebuild
Update debian changelog