random: remove whitespace and reorder includes

This is purely cosmetic. Future work involves figuring out which of
these headers we need and which we don't.

Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>