[Scudo][CMake] Add -fno-lto to Scudo libraries

-fno-lto is in SANITIZER_COMMON_CFLAGS but not here.
Don't use SANITIZER_COMMON_CFLAGS because of performance issues.
See https://bugs.llvm.org/show_bug.cgi?id=46838.

Fixes
$ ninja TScudoCUnitTest-i386-Test
on an LLVM build with -DLLVM_ENABLE_LTO=Thin.
check-scudo now passes.

Reviewed By: cryptoad

Differential Revision: https://reviews.llvm.org/D84805