Remove trailing whitespace

src/build-remote/build-remote.cc

src/libexpr/attr-path.cc

src/libexpr/lexer.l

src/libexpr/nixexpr.cc

src/libmain/progress-bar.cc

src/libstore/daemon.cc

src/libstore/filetransfer.cc

src/libstore/local-store.cc

src/libstore/optimise-store.cc

src/libstore/store-api.cc

src/libutil/error.cc

src/libutil/logging.cc

src/libutil/util.cc

src/nix-daemon/nix-daemon.cc

src/nix-env/nix-env.cc

src/nix-store/nix-store.cc

src/nix/verify.cc

...esolve-system-dependencies/resolve-system-dependencies.cc