safe: Use Effective extended flags

[spencer-lunarg]

for future extending flags extensions, I think it would be better to just have the "effective" flag value in safe struct

From validation, I find the ONLY 2 reasons we want the "original" value is

1. To deduce the Location (which we can still do checking if pNext has the struct on an error)
2. when we are creating the object (so vkCreateBuffer) but at that point, we have not made a safe struct copy yet

The whole "idea" of safe struct was to make our own internal copy and I can't think (so yell at me with it if you can think) why Safe Struct should not have the effective flag value

[spencer-lunarg]

... so this failed, going create_info.ptr() you get a VkBufferCreateInfo that is not correct because the usage field went from 32 bits to 64 bits messing up the struct

decided this isn't the place to do it... Quake 2 level doom as I said