Instrumented libraries: do not use FORTIFY_SOURCE when building udev.

Also, address a nit from a prior post-commit review.

BUG=414189
TBR=glider@chromium.org
NOTRY=true

Review URL: https://codereview.chromium.org/755653006

Cr-Original-Commit-Position: refs/heads/master@{#306897}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: ea75a9de16c6f45d6ce4a7ce3e1bbf8e0070c0ae
2 files changed