net/netlink: lockdep_genl_is_held can be boolean

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

No functional change.

Signed-off-by: Yaowei Bai <bywxiaobai@163.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c
index 75724a9..bc0e504 100644
--- a/net/netlink/genetlink.c
+++ b/net/netlink/genetlink.c
@@ -39,7 +39,7 @@
 EXPORT_SYMBOL(genl_unlock);
 
 #ifdef CONFIG_LOCKDEP
-int lockdep_genl_is_held(void)
+bool lockdep_genl_is_held(void)
 {
 	return lockdep_is_held(&genl_mutex);
 }