treewide: Use makeBinPath

pkgs/tools/typesetting/djvu2pdf/default.nix

@@ -14,7 +14,7 @@ stdenv.mkDerivation rec {
   installPhase = ''
     mkdir -p $out/bin
     cp -p djvu2pdf $out/bin
-    wrapProgram $out/bin/djvu2pdf --prefix PATH : ${ghostscript}/bin:${djvulibre.bin}/bin:${which}/bin
+    wrapProgram $out/bin/djvu2pdf --prefix PATH : ${stdenv.lib.makeBinPath [ ghostscript djvulibre which ]}
 
     mkdir -p $out/man/man1
     cp -p djvu2pdf.1.gz $out/man/man1

pkgs/tools/typesetting/docbook2odf/default.nix

@@ -26,7 +26,7 @@ stdenv.mkDerivation rec {
     sed -i "s|/usr/share/docbook2odf|$out/share/docbook2odf|" "$out/bin/docbook2odf"
 
     wrapProgram "$out/bin/docbook2odf" \
-      --prefix PATH : "${zip}/bin:${libxslt}/bin" \
+      --prefix PATH : "${stdenv.lib.makeBinPath [ zip libxslt ]}" \
       --prefix PERL5PATH : "${stdenv.lib.makePerlPath [PerlMagick]}"
   '';
 

pkgs/tools/typesetting/xmlto/default.nix

@@ -25,7 +25,7 @@ stdenv.mkDerivation rec {
 
   postInstall = ''
     wrapProgram "$out/bin/xmlto" \
-       --prefix PATH : "${libxslt.bin}/bin:${libxml2.bin}/bin:${getopt}/bin"
+       --prefix PATH : "${stdenv.lib.makeBinPath [ libxslt libxml2 getopt ]}"
 
     # `w3m' is needed for HTML to text conversions.
     substituteInPlace "$out/share/xmlto/format/docbook/txt" \