fsi: fsi_master_class can be static

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Fixes: 0604d53d4da8 ("fsi: Add fsi-master class")
Signed-off-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20191108051945.7109-7-joel@jms.id.auSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/fsi/fsi-core.c

@@ -1272,7 +1272,7 @@ static struct attribute *master_attrs[] = {
 
 ATTRIBUTE_GROUPS(master);
 
-struct class fsi_master_class = {
+static struct class fsi_master_class = {
 	.name = "fsi-master",
 	.dev_groups = master_groups,
 };