random: check for crng_init == 0 in add_device_randomness()

This has no real functional change, as crng_pre_init_inject() (and
before that, crng_slow_init()) always checks for == 0, not >= 2. So
correct the outer unlocked change to reflect that. Before this used
crng_ready(), which was not correct.

Cc: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

drivers/char/random.c

@@ -1020,7 +1020,7 @@ void add_device_randomness(const void *buf, size_t size)
 	unsigned long time = random_get_entropy() ^ jiffies;
 	unsigned long flags;
 
-	if (!crng_ready() && size)
+	if (crng_init == 0 && size)
 		crng_pre_init_inject(buf, size, false, false);
 
 	spin_lock_irqsave(&input_pool.lock, flags);