ceph: define ceph_auth_handshake type

The definitions for the ceph_mds_session and ceph_osd both contain
five fields related only to "authorizers."  Encapsulate those fields
into their own struct type, allowing for better isolation in some
upcoming patches.

Fix the #includes in "linux/ceph/osd_client.h" to lay out their more
complete canonical path.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
diff --git a/fs/ceph/mds_client.h b/fs/ceph/mds_client.h
index 8c7c04e..dd26846 100644
--- a/fs/ceph/mds_client.h
+++ b/fs/ceph/mds_client.h
@@ -11,6 +11,7 @@
 #include <linux/ceph/types.h>
 #include <linux/ceph/messenger.h>
 #include <linux/ceph/mdsmap.h>
+#include <linux/ceph/auth.h>
 
 /*
  * Some lock dependencies:
@@ -113,9 +114,7 @@
 
 	struct ceph_connection s_con;
 
-	struct ceph_authorizer *s_authorizer;
-	void             *s_authorizer_buf, *s_authorizer_reply_buf;
-	size_t            s_authorizer_buf_len, s_authorizer_reply_buf_len;
+	struct ceph_auth_handshake s_auth;
 
 	/* protected by s_gen_ttl_lock */
 	spinlock_t        s_gen_ttl_lock;