bchunk: fix recent CVEs, simplify installPhase

For details, see:

https://bugs.gentoo.org/635898

https://nvd.nist.gov/vuln/detail/CVE-2017-15953
https://nvd.nist.gov/vuln/detail/CVE-2017-15954
https://nvd.nist.gov/vuln/detail/CVE-2017-15955

https://github.com/extramaster/bchunk/issues/2
https://github.com/extramaster/bchunk/issues/3
https://github.com/extramaster/bchunk/issues/4

pkgs/tools/cd-dvd/bchunk/default.nix

@@ -8,20 +8,16 @@ stdenv.mkDerivation rec {
     sha256 = "0pcbyx3689cbl23dcij497hb3q5f1wmki7cxic5nzldx71g9vp5g";
   };
 
-  preConfigure =
-    ''
-      substituteInPlace Makefile \
-        --replace "-o root -g root" "" \
-        --replace "-o bin -g bin" ""
-    '';
+  patches = [ ./CVE-2017-15953.patch ./CVE-2017-15955.patch ];
 
-  makeFlags = "PREFIX=$(out) MAN_DIR=$(out)/share/man";
+  installPhase = ''
+    install -Dt $out/bin bchunk
+    install -Dt $out/share/man/man1 bchunk.1    
+  '';
 
-  preInstall = "mkdir -p $out/bin $out/share/man/man1";
-
-  meta = {
+  meta = with stdenv.lib; {
     homepage = http://he.fi/bchunk/;
-    description = "A program that converts CD-ROM images in BIN/CUE format into a set of ISO and CDR tracks";
-    platforms = stdenv.lib.platforms.linux;
+    description = "A program that converts CD images in BIN/CUE format into a set of ISO and CDR tracks";
+    platforms = platforms.unix;
   };
 }