netns: Replace zero-length array with DECLARE_FLEX_ARRAY() helper

Zero-length arrays are deprecated and we are moving towards adopting C99 flexible-array members, instead. So, replace zero-length arrays declarations in anonymous union with the new DECLARE_FLEX_ARRAY() helper macro.

This helper allows for flexible-array members in unions.

---
 include/net/netns/generic.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

index 7ce68183f6e1..00c399edeed1 100644
@@ -33,7 +33,7 @@ struct net_generic {
 			struct rcu_head rcu;
 		} s;
 
-		void *ptr[0];
+		DECLARE_FLEX_ARRAY(void *, ptr);
 	};
 };
 

2.34.1

Thanks! Yeah, I tripped over this one myself while testing -fstrict-flex-arrays.

Kees Cook