Revert "take out unused variables"
Revert "take out unused variables"

This reverts commit e5752ff9b322c665a7393d6109c2da7ad6ee2523.

The variables i and n are used in the `#if !__GLIBC_PREREQ(2, 7)`
branch.

Closes gh-1586.

xianyi/OpenBLAS,xianyi/OpenBLAS,xianyi/OpenBLAS,xianyi/OpenBLAS,xianyi/OpenBLAS,xianyi/OpenBLAS,xianyi/OpenBLAS,xianyi/OpenBLAS