net: core: change return type of pskb_may_pull to bool

This function de-facto returns a bool, so let's change the return type
accordingly.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/skbuff.h

@@ -2261,12 +2261,12 @@ static inline void *pskb_pull(struct sk_buff *skb, unsigned int len)
 	return unlikely(len > skb->len) ? NULL : __pskb_pull(skb, len);
 }
 
-static inline int pskb_may_pull(struct sk_buff *skb, unsigned int len)
+static inline bool pskb_may_pull(struct sk_buff *skb, unsigned int len)
 {
 	if (likely(len <= skb_headlen(skb)))
-		return 1;
+		return true;
 	if (unlikely(len > skb->len))
-		return 0;
+		return false;
 	return __pskb_pull_tail(skb, len - skb_headlen(skb)) != NULL;
 }