fbvnc: cleanup, fix cross compilation

pkgs/tools/admin/fbvnc/default.nix

@@ -1,30 +1,38 @@
-{lib, stdenv, fetchFromGitHub}:
+{ lib
+, stdenv
+, fetchFromGitHub
+}:
+
 stdenv.mkDerivation rec {
-  name = "${pname}-${version}";
   pname = "fbvnc";
   version = "1.0.2";
 
   src = fetchFromGitHub {
     owner = "zohead";
     repo = pname;
-    sha256 = "0lkr4j1wsa05av2g9w99rr9w4j4k7a21vp36x0a3h50y8bmgwgm1";
     rev = "783204ff6c92afec33d6d36f7e74f1fcf2b1b601";
+    hash = "sha256-oT7+6kIeFDgU6GbcHYQ6k0jCU84p8fTEVgUozYMkeVI=";
   };
 
-  buildInputs = [];
+  makeFlags = [
+    "CC:=$(CC)"
+  ];
 
   installPhase = ''
-    mkdir -p "$out/bin"
-    cp fbvnc "$out/bin"
-    mkdir -p "$out/share/doc/${pname}"
-    cp README* "$out/share/doc/${pname}"
+    runHook preInstall
+
+    install -Dm555 fbvnc     -t "$out/bin"
+    install -Dm444 README.md -t "$out/share/doc/fbvnc"
+
+    runHook postInstall
   '';
 
   meta = {
     description = "Framebuffer VNC client";
     license = lib.licenses.bsd3;
-    maintainers = [lib.maintainers.raskin];
+    maintainers = [ lib.maintainers.raskin ];
     platforms = lib.platforms.linux;
     homepage = "https://github.com/zohead/fbvnc/";
+    mainProgram = "fbvnc";
   };
 }