Comment # 4 on bug 1189782 from Guilherme Moro

The problem comes from the 10_linux helper script from grub that is looking for
CONFIG_FB_EFI configuration in the kernel, but the path for the configuration
file is broken since the move from /lib/modules to /usr/lib/modules.
Didn't track down exactly how it's broken yet, but just so you guys know not to
search anywhere else.