libceph: Rename hmac_sha256() to ceph_hmac_sha256()

Rename hmac_sha256() to ceph_hmac_sha256(), to avoid a naming conflict
with the upcoming hmac_sha256() library function.

This code will be able to use the HMAC-SHA256 library, but that's left
for a later commit.

Acked-by: Ard Biesheuvel <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Eric Biggers <[e-mail]>

net/ceph/messenger_v2.c

···
 	return 0;  /* auth_x, secure mode */
 }
 
-static int hmac_sha256(struct ceph_connection *con, const struct kvec *kvecs,
-		       int kvec_cnt, u8 *hmac)
+static int ceph_hmac_sha256(struct ceph_connection *con,
+			    const struct kvec *kvecs, int kvec_cnt, u8 *hmac)
 {
 	SHASH_DESC_ON_STACK(desc, con->v2.hmac_tfm);  /* tfm arg is ignored */
 	int ret;
···
 	if (!buf)
 		return -ENOMEM;
 
-	ret = hmac_sha256(con, con->v2.in_sign_kvecs, con->v2.in_sign_kvec_cnt,
-			  CTRL_BODY(buf));
+	ret = ceph_hmac_sha256(con, con->v2.in_sign_kvecs,
+			       con->v2.in_sign_kvec_cnt, CTRL_BODY(buf));
 	if (ret)
 		return ret;
 
···
 		return -EINVAL;
 	}
 
-	ret = hmac_sha256(con, con->v2.out_sign_kvecs,
-			  con->v2.out_sign_kvec_cnt, hmac);
+	ret = ceph_hmac_sha256(con, con->v2.out_sign_kvecs,
+			       con->v2.out_sign_kvec_cnt, hmac);
 	if (ret)
 		return ret;