libceph: rename MAX_OBJ_NAME_SIZE to CEPH_MAX_OID_NAME_LEN

In preparation for adding oid abstraction, rename MAX_OBJ_NAME_SIZE to
CEPH_MAX_OID_NAME_LEN.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
diff --git a/net/ceph/osd_client.c b/net/ceph/osd_client.c
index 7130c5c..a053e7e 100644
--- a/net/ceph/osd_client.c
+++ b/net/ceph/osd_client.c
@@ -338,7 +338,7 @@
 	msg_size = 4 + 4 + 8 + 8 + 4+8;
 	msg_size += 2 + 4 + 8 + 4 + 4; /* oloc */
 	msg_size += 1 + 8 + 4 + 4;     /* pg_t */
-	msg_size += 4 + MAX_OBJ_NAME_SIZE;
+	msg_size += 4 + CEPH_MAX_OID_NAME_LEN; /* oid */
 	msg_size += 2 + num_ops*sizeof(struct ceph_osd_op);
 	msg_size += 8;  /* snapid */
 	msg_size += 8;  /* snap_seq */