crypto: algapi - convert cra_refcnt to refcount_t

Reference counters should use refcount_t rather than atomic_t, since the
refcount_t implementation can prevent overflows, reducing the
exploitability of reference leak bugs.  crypto_alg.cra_refcount is a
reference counter with the usual semantics, so switch it over to
refcount_t.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/crypto/internal.h b/crypto/internal.h
index ae65e5f..1388af6 100644
--- a/crypto/internal.h
+++ b/crypto/internal.h
@@ -105,13 +105,13 @@ int crypto_type_has_alg(const char *name, const struct crypto_type *frontend,
 
 static inline struct crypto_alg *crypto_alg_get(struct crypto_alg *alg)
 {
-	atomic_inc(&alg->cra_refcnt);
+	refcount_inc(&alg->cra_refcnt);
 	return alg;
 }
 
 static inline void crypto_alg_put(struct crypto_alg *alg)
 {
-	if (atomic_dec_and_test(&alg->cra_refcnt) && alg->cra_destroy)
+	if (refcount_dec_and_test(&alg->cra_refcnt) && alg->cra_destroy)
 		alg->cra_destroy(alg);
 }