ARM: 8522/1: drivers: nvdimm: ensure no negative value gets returned on positive match

This patch ensures that existing bus match callbacks don't return
negative values (which might be interpreted as potential errors in the
future) in case of positive match.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/drivers/nvdimm/bus.c b/drivers/nvdimm/bus.c
index 7e2c43f..2b2181c 100644
--- a/drivers/nvdimm/bus.c
+++ b/drivers/nvdimm/bus.c
@@ -62,7 +62,7 @@
 {
 	struct nd_device_driver *nd_drv = to_nd_device_driver(drv);
 
-	return test_bit(to_nd_device_type(dev), &nd_drv->type);
+	return !!test_bit(to_nd_device_type(dev), &nd_drv->type);
 }
 
 static struct module *to_bus_provider(struct device *dev)