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