Fix initrd breaking by recent repeatable-builds changes

See the comments at https://github.com/NixOS/nixpkgs/commit/f67015cae49400eba539b9ec8b9920643581c77c
for more information.

Please note: this makes initrd unrepeatable again, but most people will prefer that above an unbootable system.

pkgs/build-support/kernel/cpio-clean.pl

@@ -11,9 +11,6 @@ my $IN = \*STDIN;
 my $ino = 1;
 $cpio->read_with_handler($IN, sub {
         my ($e) = @_;
-        $e->{inode} = $ino;
-        $ino++;
-        $e->{nlink} = 1;
         $e->{mtime} = 1;
 	$cpio->write_one(\*STDOUT, $e);
     });