ceph: messenger: reduce args to create_authorizer

Make use of the new ceph_auth_handshake structure in order to reduce
the number of arguments passed to the create_authorizor method in
ceph_auth_client_ops.  Use a local variable of that type as a
shorthand in the get_authorizer method definitions.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
diff --git a/include/linux/ceph/auth.h b/include/linux/ceph/auth.h
index 5b774d1..d4080f3 100644
--- a/include/linux/ceph/auth.h
+++ b/include/linux/ceph/auth.h
@@ -51,9 +51,7 @@
 	 * the response to authenticate the service.
 	 */
 	int (*create_authorizer)(struct ceph_auth_client *ac, int peer_type,
-				 struct ceph_authorizer **a,
-				 void **buf, size_t *len,
-				 void **reply_buf, size_t *reply_len);
+				 struct ceph_auth_handshake *auth);
 	int (*verify_authorizer_reply)(struct ceph_auth_client *ac,
 				       struct ceph_authorizer *a, size_t len);
 	void (*destroy_authorizer)(struct ceph_auth_client *ac,