boost: Kill unnecessary 'lib' output

This was split in somewhere pre-2014 without the current infra which
automates parts of this, in particular the output propagation.

pkgs/development/interpreters/pixie/default.nix

@@ -22,7 +22,7 @@ let
     url = "https://bitbucket.org/pypy/pypy/get/${pypy-tag}.tar.bz2";
     sha256 = "1cs9xqs1rmzdcnwxxkbvy064s5cbp6vvzhn2jmyzh5kg4di1r3bn";
   };
-  libs = [ libffi libedit libuv boost.dev boost.lib zlib ];
+  libs = [ libffi libedit libuv boost.dev boost.out zlib ];
   include-path = stdenv.lib.concatStringsSep ":"
                    (map (p: "${p}/include") libs);
   library-path = stdenv.lib.concatStringsSep ":"
@@ -47,7 +47,7 @@ let
     patchPhase = ''
       (cd pixie-src
        patch -p1 < ${./load_paths.patch}
-       libraryPaths='["${libuv}" "${libedit}" "${libffi}" "${boost.dev}" "${boost.lib}" "${zlib}"]'
+       libraryPaths='["${libuv}" "${libedit}" "${libffi}" "${boost.dev}" "${boost.out}" "${zlib}"]'
        export libraryPaths
        substituteAllInPlace ./pixie/ffi-infer.pxi)
     '';