Remove Windows linker flags from the CMake link flags test as the
test doesn't actually pass the flags to the VS linker.

Change-Id: I5d546afcb80a49e39143078bc8f0855b0ba0f7e8
Reviewed-on: https://code.wireshark.org/review/5384
Petri-Dish: Graham Bloice <graham.bloice@trihedral.com>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Graham Bloice <graham.bloice@trihedral.com>