NTB: namespacecheck cleanups

Declare ntb_bus_type static to remove it from name space, and remove
unused ntb_get_max_spads function.  Found via `make namespacecheck`.

Signed-off-by: Jon Mason <jon.mason@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/ntb/ntb_transport.c b/drivers/ntb/ntb_transport.c
index c0eca02..903a72e 100644
--- a/drivers/ntb/ntb_transport.c
+++ b/drivers/ntb/ntb_transport.c
@@ -212,7 +212,7 @@
 	return 0;
 }
 
-struct bus_type ntb_bus_type = {
+static struct bus_type ntb_bus_type = {
 	.name = "ntb_bus",
 	.match = ntb_match_bus,
 	.probe = ntb_client_probe,