libceph: initialize msgpool message types

Initialize the type field for messages in a msgpool.  The caller was doing
this for osd ops, but not for the reply messages.

Reported-by: Alex Elder <elder@inktank.com>
Signed-off-by: Sage Weil <sage@inktank.com>
diff --git a/include/linux/ceph/msgpool.h b/include/linux/ceph/msgpool.h
index a362605f..09fa96b 100644
--- a/include/linux/ceph/msgpool.h
+++ b/include/linux/ceph/msgpool.h
@@ -11,10 +11,11 @@
 struct ceph_msgpool {
 	const char *name;
 	mempool_t *pool;
+	int type;               /* preallocated message type */
 	int front_len;          /* preallocated payload size */
 };
 
-extern int ceph_msgpool_init(struct ceph_msgpool *pool,
+extern int ceph_msgpool_init(struct ceph_msgpool *pool, int type,
 			     int front_len, int size, bool blocking,
 			     const char *name);
 extern void ceph_msgpool_destroy(struct ceph_msgpool *pool);