page 77, incorrect claim about a method on intel platforms

[pbalcer]

https://link.springer.com/chapter/10.1007/978-1-4842-4932-1_6

The sentence For example, on Intel platforms, pmem_drain is an empty function. is not correct. It was taken from libpmem's man page, where it has been replaced with: For example, on Intel platforms with eADR, pmem_flush() is an empty function.