[sanitizer] Remove low-hanging-fruit dead code

Summary:
Going through the dead code findings, the code removed in this CL appears to be
pretty straightforward to remove, and seems to be some leftover from previous
refactors.

Reviewers: alekseyshl, eugenis

Reviewed By: alekseyshl

Subscribers: kubamracek, delcypher, #sanitizers, llvm-commits

Differential Revision: https://reviews.llvm.org/D45704

llvm-svn: 330190