net: add __must_check to skb_put_padto()

skb_put_padto() and __skb_put_padto() callers
must check return values or risk use-after-free.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/skbuff.h

@@ -3223,8 +3223,9 @@ static inline int skb_padto(struct sk_buff *skb, unsigned int len)
  *	is untouched. Otherwise it is extended. Returns zero on
  *	success. The skb is freed on error if @free_on_error is true.
  */
-static inline int __skb_put_padto(struct sk_buff *skb, unsigned int len,
-				  bool free_on_error)
+static inline int __must_check __skb_put_padto(struct sk_buff *skb,
+					       unsigned int len,
+					       bool free_on_error)
 {
 	unsigned int size = skb->len;
 
@@ -3247,7 +3248,7 @@ static inline int __skb_put_padto(struct sk_buff *skb, unsigned int len,
  *	is untouched. Otherwise it is extended. Returns zero on
  *	success. The skb is freed on error.
  */
-static inline int skb_put_padto(struct sk_buff *skb, unsigned int len)
+static inline int __must_check skb_put_padto(struct sk_buff *skb, unsigned int len)
 {
 	return __skb_put_padto(skb, len, true);
 }