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/include/linux/genetlink.h b/include/linux/genetlink.h
index 09460d6..a4c61cb 100644
--- a/include/linux/genetlink.h
+++ b/include/linux/genetlink.h
@@ -8,7 +8,7 @@
 extern void genl_lock(void);
 extern void genl_unlock(void);
 #ifdef CONFIG_LOCKDEP
-extern int lockdep_genl_is_held(void);
+extern bool lockdep_genl_is_held(void);
 #endif
 
 /* for synchronisation between af_netlink and genetlink */