boot: Rework GUID handling

This stops using global GUID variables provided by gnu-efi. The globals
presumably exist to make EFI calls easier. But these GUIDs are just
128bits, so it's cheap to just put them on the stack when needed. C99
compound literals makes this even easier.

This also adds a convenience macro to create GUID pointers and uses it
everywhere. Not forcing a GUID definition to be a compound literal makes
them easier to use when assigning them to variables:
    EFI_GUID before = *SOME_CONST_GUID;
    EFI_GUID after = SOME_GUID;

And MAKE_GUID_PTR() makes it more explicit what is happening. It was
easy to confuse the old code as a cast:
    before(&(EFI_GUID) SOME_GUID);
    after(MAKE_GUID_PTR(SOME));

0 files changed, 0 insertions, 0 deletions