build-support/emacs: make version non-optional

I do not think there is a good reason for it to be optional.

There were only two packages without a version attr.  The version attr
is added to them in this patch.

pkgs/applications/editors/emacs/elisp-packages/manual-packages/control-lock/default.nix

@@ -8,6 +8,8 @@ trivialBuild {
     hash = "sha256-JCrmS3FSGDHSR+eAR0X/uO0nAgd3TUmFxwEVH5+KV+4=";
   };
 
+  version = "1.1.2";
+
   meta = {
     description = "Like caps-lock, but for your control key.  Give your pinky a rest!";
     homepage = "https://www.emacswiki.org/emacs/control-lock.el";

pkgs/applications/editors/emacs/elisp-packages/manual-packages/perl-completion/default.nix

@@ -10,6 +10,8 @@ trivialBuild {
     sha256 = "0x6qsgs4hm87k0z9q3g4p6508kc3y123j5jayll3jf3lcl2vm6ks";
   };
 
+  version = "1.10";
+
   meta = {
     broken = true;
     description = "Minor mode provides useful features for editing perl codes";

pkgs/build-support/emacs/generic.nix

@@ -3,7 +3,7 @@
 { lib, stdenv, emacs, texinfo, writeText, gcc, ... }:
 
 { pname
-, version ? null
+, version
 , buildInputs ? []
 , packageRequires ? []
 , meta ? {}
@@ -20,7 +20,7 @@ let
 in
 
 stdenv.mkDerivation ({
-  name = "emacs-${pname}${lib.optionalString (version != null) "-${version}"}";
+  name = "emacs-${pname}-${version}";
 
   unpackCmd = ''
     case "$curSrc" in