cleanup whitespace and commas

* [] is now [ ]
* {} is now { }
* commas in arglists go at end of line not beginning

In short, I ran the whole thing through nixfmt-rfc-style but only
accepted about 30% of its changes. I might grow accustomed to more
of it over time

tests/ci.nix

@@ -5,7 +5,7 @@
   pppoe = import ./pppoe/test.nix;
   jffs2 = import ./jffs2/test.nix;
   ext4 = import ./ext4/test.nix;
-  min-copy-closure =  import ./min-copy-closure/test.nix;
+  min-copy-closure = import ./min-copy-closure/test.nix;
   fennel = import ./fennel/test.nix;
   tftpboot = import ./tftpboot/test.nix;
   updown = import ./updown/test.nix;