{anydesk,btrbk,nncp}: simplify update script

- There is no need to pass pname and version arguments

- The version lister does not use positional arguments anymore, but
option arguments. Removed the echo command to fix an issue regarding
this.

pkgs/applications/networking/remote/anydesk/default.nix

@@ -30,9 +30,7 @@ in stdenv.mkDerivation rec {
 
   passthru = {
     updateScript = genericUpdater {
-      inherit pname version;
       versionLister = writeShellScript "anydesk-versionLister" ''
-        echo "# Versions for $1:" >> "$2"
         curl -s https://anydesk.com/en/downloads/linux \
           | grep "https://[a-z0-9._/-]*-amd64.tar.gz" -o \
           | uniq \

pkgs/tools/backup/btrbk/default.nix

@@ -56,9 +56,7 @@ stdenv.mkDerivation rec {
   passthru.tests.btrbk = nixosTests.btrbk;
 
   passthru.updateScript = genericUpdater {
-    inherit pname version;
     versionLister = writeShellScript "btrbk-versionLister" ''
-      echo "# Versions for $1:" >> "$2"
       ${curl}/bin/curl -s https://digint.ch/download/btrbk/releases/ | ${perl}/bin/perl -lne 'print $1 if /btrbk-([0-9.]*)\.tar/'
     '';
   };

pkgs/tools/misc/nncp/default.nix

@@ -30,9 +30,7 @@ stdenv.mkDerivation rec {
   enableParallelBuilding = true;
 
   passthru.updateScript = genericUpdater {
-    inherit pname version;
     versionLister = writeShellScript "nncp-versionLister" ''
-      echo "# Versions for $1:" >> "$2"
       ${curl}/bin/curl -s ${meta.downloadPage} | ${perl}/bin/perl -lne 'print $1 if /Release.*>([0-9.]+)</'
     '';
   };