display7seg: BKL pushdown

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
diff --git a/drivers/sbus/char/display7seg.c b/drivers/sbus/char/display7seg.c
index 3279a1b..d8f5c0c 100644
--- a/drivers/sbus/char/display7seg.c
+++ b/drivers/sbus/char/display7seg.c
@@ -94,6 +94,7 @@
 {
 	if (D7S_MINOR != iminor(inode))
 		return -ENODEV;
+	cycle_kernel_lock();
 	atomic_inc(&d7s_users);
 	return 0;
 }