net: Make msg_zerocopy_alloc static

msg_zerocopy_alloc is only used by msg_zerocopy_realloc; remove the
export and make static in skbuff.c
Signed-off-by: David Ahern <dsahern@kernel.org>
Acked-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Link: https://lore.kernel.org/r/20220504170947.18773-1-dsahern@kernel.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

include/linux/skbuff.h

@@ -1665,7 +1665,6 @@ static inline void skb_set_end_offset(struct sk_buff *skb, unsigned int offset)
 }
 #endif
 
-struct ubuf_info *msg_zerocopy_alloc(struct sock *sk, size_t size);
 struct ubuf_info *msg_zerocopy_realloc(struct sock *sk, size_t size,
 				       struct ubuf_info *uarg);
 

net/core/skbuff.c

@@ -1165,7 +1165,7 @@ void mm_unaccount_pinned_pages(struct mmpin *mmp)
 }
 EXPORT_SYMBOL_GPL(mm_unaccount_pinned_pages);
 
-struct ubuf_info *msg_zerocopy_alloc(struct sock *sk, size_t size)
+static struct ubuf_info *msg_zerocopy_alloc(struct sock *sk, size_t size)
 {
 	struct ubuf_info *uarg;
 	struct sk_buff *skb;
@@ -1196,7 +1196,6 @@ struct ubuf_info *msg_zerocopy_alloc(struct sock *sk, size_t size)
 
 	return uarg;
 }
-EXPORT_SYMBOL_GPL(msg_zerocopy_alloc);
 
 static inline struct sk_buff *skb_from_uarg(struct ubuf_info *uarg)
 {