treewide: Use makeBinPath

pkgs/applications/misc/avrdudess/default.nix

@@ -23,7 +23,7 @@ stdenv.mkDerivation rec {
     export LD_LIBRARY_PATH="${stdenv.lib.makeLibraryPath [gtk mono]}"
     # We need PATH from user env for xdg-open to find its tools, which
     # typically depend on the currently running desktop environment.
-    export PATH="${avrgcclibc}/bin:${avrdude}/bin:${xdg_utils}/bin:\$PATH"
+    export PATH="${stdenv.lib.makeBinPath [ avrgcclibc avrdude xdg_utils ]}:\$PATH"
 
     # avrdudess must have its resource files in its current working directory
     cd $out/avrdudess && exec ${mono}/bin/mono "$out/avrdudess/avrdudess.exe" "\$@"