iotools: Fix werror and refactor definition

pkgs/by-name/io/iotools/001-fix-werror-in-sprintf.patch

@@ -0,0 +1,13 @@
+diff --git a/commands.c b/commands.c
+index a83f1d5..b3f217a 100644
+--- a/commands.c
++++ b/commands.c
+@@ -152,1 +152,7 @@ build_symlink_name(const char *path_to_bin, const struct cmd_info *cmd)
+-	snprintf(link_name, FILENAME_MAX, "%s/%s", path_to_bin, cmd->name);
++	int result = snprintf(link_name, FILENAME_MAX, "%s/%s", path_to_bin, cmd->name);
++
++	if (result >= FILENAME_MAX) {
++		link_name[FILENAME_MAX - 1] = '\0';
++	} else if (result < 0) {
++		link_name[0] = '\0';
++	}

pkgs/by-name/io/iotools/package.nix

@@ -4,7 +4,7 @@
   fetchFromGitHub,
 }:
 
-stdenv.mkDerivation {
+stdenv.mkDerivation (finalAttrs: {
   pname = "iotools";
   version = "unstable-2017-12-11";
 
@@ -15,6 +15,8 @@ stdenv.mkDerivation {
     hash = "sha256-tlGXJn3n27mQDupMIVYDd86YaWazVwel/qs0QqCy1W8=";
   };
 
+  patches = [ ./001-fix-werror-in-sprintf.patch ];
+
   makeFlags = [
     "DEBUG=0"
     "STATIC=0"
@@ -24,7 +26,7 @@ stdenv.mkDerivation {
     install -Dm755 iotools -t $out/bin
   '';
 
-  meta = with lib; {
+  meta = {
     description = "Set of simple command line tools which allow access to
       hardware device registers";
     longDescription = ''
@@ -35,12 +37,12 @@ stdenv.mkDerivation {
       operations.
     '';
     homepage = "https://github.com/adurbin/iotools";
-    license = licenses.gpl2Only;
-    maintainers = with maintainers; [ felixsinger ];
+    license = lib.licenses.gpl2Only;
+    maintainers = with lib.maintainers; [ felixsinger ];
     platforms = [
       "x86_64-linux"
       "i686-linux"
     ];
     mainProgram = "iotools";
   };
-}
+})