lame: remove useless nulls

pkgs/development/libraries/lame/default.nix

@@ -1,21 +1,16 @@
 { lib, stdenv, fetchurl
-, nasmSupport ? true, nasm ? null # Assembly optimizations
+, nasmSupport ? true, nasm # Assembly optimizations
 , cpmlSupport ? true # Compaq's fast math library
-#, efenceSupport ? false, libefence ? null # Use ElectricFence for malloc debugging
-, sndfileFileIOSupport ? false, libsndfile ? null # Use libsndfile, instead of lame's internal routines
+#, efenceSupport ? false, libefence # Use ElectricFence for malloc debugging
+, sndfileFileIOSupport ? false, libsndfile # Use libsndfile, instead of lame's internal routines
 , analyzerHooksSupport ? true # Use analyzer hooks
 , decoderSupport ? true # mpg123 decoder
 , frontendSupport ? true # Build the lame executable
-#, mp3xSupport ? false, gtk1 ? null # Build GTK frame analyzer
+#, mp3xSupport ? false, gtk1 # Build GTK frame analyzer
 , mp3rtpSupport ? false # Build mp3rtp
 , debugSupport ? false # Debugging (disables optimizations)
 }:
 
-assert nasmSupport -> (nasm != null);
-#assert efenceSupport -> (libefence != null);
-assert sndfileFileIOSupport -> (libsndfile != null);
-#assert mp3xSupport -> (analyzerHooksSupport && (gtk1 != null));
-
 let
   mkFlag = optSet: flag: if optSet then "--enable-${flag}" else "--disable-${flag}";
 in