x86_64: Remove end of line trailing spaces

This commit remove trailing space introduced by following commit.

commit a775a7a3
Author: Noah Goldstein <goldstein.w.n@gmail.com>
Date:   Wed Jun 23 01:56:29 2021 -0400

    x86: Fix overflow bug in wcsnlen-sse4_1 and wcsnlen-avx2 [BZ #27974]