crypto: In crypto_add_alg(), 'exact' wants to be initialized to 0

We declare 'exact' without initializing it and then do:

[...]
	if (strlen(p->cru_driver_name))
		exact = 1;

	if (priority && !exact)
		return -EINVAL;

[...]

If the first 'if' is not true, then the second will test an
uninitialized 'exact'.
As far as I can tell, what we want is for 'exact' to be initialized to
0 (zero/false).

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Acked-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>