Unable to boot after kernel (3.19) upgrade on Ubuntu. Here's the fix:

1. Add copy_modules_dir kernel/ubuntu/i915 to /usr/share/initramfs-tools/hooks/framebuffer.
2. Then run update-initramfs -k all -u.
3. Profit.

Fix found here: https://bugs.launchpad.net/ubuntu/+source/cryptsetup/+bug/1500751