[lld] [lld][Mips] Remove signed range check for R_MICROMIPS_26_S1 (PR #228880)

[Fangrui Song via llvm-commits]

MaskRay wrote:

> I thought this one was small enough to commit directly, ...

It's often ok in many other areas, but not in lld, libc++, libc++abi, libunwind, where there is a very rigid review workflow.

The commit message formatting is also poor (forced wrapping at 72 columns), an issue often caused by agentic coding tools.

https://github.com/llvm/llvm-project/pull/228880