net/core: lockdep_rtnl_is_held can be boolean

This patch makes lockdep_rtnl_is_held return bool due to this
particular function only using either one or zero as its return
value.

In another patch lockdep_is_held is also made return bool.

No functional change.

Signed-off-by: Yaowei Bai <bywxiaobai@163.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/rtnetlink.h b/include/linux/rtnetlink.h
index 39adaa9..4be5048 100644
--- a/include/linux/rtnetlink.h
+++ b/include/linux/rtnetlink.h
@@ -33,11 +33,11 @@
 extern struct mutex net_mutex;
 
 #ifdef CONFIG_PROVE_LOCKING
-extern int lockdep_rtnl_is_held(void);
+extern bool lockdep_rtnl_is_held(void);
 #else
-static inline int lockdep_rtnl_is_held(void)
+static inline bool lockdep_rtnl_is_held(void)
 {
-	return 1;
+	return true;
 }
 #endif /* #ifdef CONFIG_PROVE_LOCKING */