[PATCH -next] nvdimm: make nd_class static

[ruanjinjie]

The symbol is not used outside of the file, so mark it static.

Fixes the following warning:

drivers/nvdimm/bus.c:28:14: warning: symbol 'nd_class' was not declared. Should it be static?

Signed-off-by: ruanjinjie <ruanjinjie@xxxxxxxxxx>
---
 drivers/nvdimm/bus.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/nvdimm/bus.c b/drivers/nvdimm/bus.c
index b38d0355b0ac..1bf5f77e6f76 100644
--- a/drivers/nvdimm/bus.c
+++ b/drivers/nvdimm/bus.c
@@ -25,7 +25,7 @@
 
 int nvdimm_major;
 static int nvdimm_bus_major;
-struct class *nd_class;
+static struct class *nd_class;
 static DEFINE_IDA(nd_ida);
 
 static int to_nd_device_type(struct device *dev)
-- 
2.25.1