crypto: salsa20-generic - don't unnecessarily use atomic walk

salsa20-generic doesn't use SIMD instructions or otherwise disable
preemption, so passing atomic=true to skcipher_walk_virt() is
unnecessary.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto/salsa20_generic.c

@@ -159,7 +159,7 @@ static int salsa20_crypt(struct skcipher_request *req)
 	u32 state[16];
 	int err;
 
-	err = skcipher_walk_virt(&walk, req, true);
+	err = skcipher_walk_virt(&walk, req, false);
 
 	salsa20_init(state, ctx, walk.iv);