change for bounding mmap range is likely not required anymore

[thestinger]

https://github.com/anthraxx/linux-hardened/commit/6cf94a91337558f3fcaaf9cc04815b156051b0a7

No longer seems required to prevent randomization from breaking by forcing exhausting the address space and then targeting a known address based on the lower bound. More testing / research required. I don't have time to spare for x86_64 though. I think it's fairly likely that stack gap changes are responsible for making it no longer required. It would be good to figure out what's happening via /proc/self/maps.