Mistake in include IS_ENABLED(CONFIG_LIVEPATCH)

[Denys Fedoryshchenko]

Hello,

I noticed that sample of livepatch is not working in 4.9.9, because in 
include,
linux/livepatch.h
it is:
#if IS_ENABLED(CONFIG_LIVEPATCH)

while config option is:
CONFIG_HAVE_LIVEPATCH=y

After editing livepatch.h sample module compiles fine

Probably that's just a typo?