_setup_env.sh: Prevent Clang sysroot detection for userprogs Prevent Clang sysroot detection for userprogs by specifying a path known not to contain a sysroot. See also: https://lore.kernel.org/linux-kbuild/20220112224342.958358-1-quic_eberman@quicinc.com/ Test: Compare .config from BUILD_CONFIG=common/build.config.gki.aarch64 ./build/build.sh Bug: 214127735 Signed-off-by: Elliot Berman <quic_eberman@quicinc.com> Change-Id: I8c23755c3d5d1c7ef12de642659afdcfb3c1e380 (cherry picked from commit e5f575376c3abcbc0cafe58746407af68b976c49)