wireless-tools: don't assume gcc, don't use ldconfig, fix cross

pkgs/os-specific/linux/wireless-tools/default.nix

···
   };
 
   preBuild = "
-    makeFlagsArray=(PREFIX=$out)
+    makeFlagsArray=(PREFIX=$out CC=$CC LDCONFIG=: AR=$AR RANLIB=$RANLIB)
   ";
 
   meta = {