[PATCH mptcp-next 3/3] tcp: make tcp_build_frag() static

[Paolo Abeni <pabeni@redhat.com>]

After the previous patch the mentioned helper is
used only inside its compilation unit: let's make
it static.

RFC -> v1:
 - preserve the tcp_build_frag() helper (Eric)

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
---
Note:
this should _replace_:
"""
Partially revert "tcp: factor out tcp_build_frag()"
"""

I did not opted for a squash to patch, as it would
still require conflicts resolution after the previous
squash-to patch. @matttbe: please let me know if you
prefer otherwise.
---
 include/net/tcp.h | 2 --
 net/ipv4/tcp.c    | 5 ++---
 2 files changed, 2 insertions(+), 5 deletions(-)

diff --git a/include/net/tcp.h b/include/net/tcp.h
index 4a96f6e0f6f8..673c3b01e287 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -330,8 +330,6 @@ int tcp_sendpage(struct sock *sk, struct page *page, int offset, size_t size,
 		 int flags);
 int tcp_sendpage_locked(struct sock *sk, struct page *page, int offset,
 			size_t size, int flags);
-struct sk_buff *tcp_build_frag(struct sock *sk, int size_goal, int flags,
-			       struct page *page, int offset, size_t *size);
 ssize_t do_tcp_sendpages(struct sock *sk, struct page *page, int offset,
 		 size_t size, int flags);
 int tcp_send_mss(struct sock *sk, int *size_goal, int flags);
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index c592454625e1..4ae43222d71f 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -963,8 +963,8 @@ void tcp_remove_empty_skb(struct sock *sk, struct sk_buff *skb)
 	}
 }
 
-struct sk_buff *tcp_build_frag(struct sock *sk, int size_goal, int flags,
-			       struct page *page, int offset, size_t *size)
+static struct sk_buff *tcp_build_frag(struct sock *sk, int size_goal, int flags,
+				      struct page *page, int offset, size_t *size)
 {
 	struct sk_buff *skb = tcp_write_queue_tail(sk);
 	struct tcp_sock *tp = tcp_sk(sk);
@@ -1064,7 +1064,6 @@ ssize_t do_tcp_sendpages(struct sock *sk, struct page *page, int offset,
 		size_t copy = size;
 
 		skb = tcp_build_frag(sk, size_goal, flags, page, offset, &copy);
-		if (!skb)
 			goto wait_for_space;
 
 		if (!copied)
-- 
2.26.3