tcp: fix tcp_should_expand_sndbuf() to use tcp_packets_in_flight()
tcp: fix tcp_should_expand_sndbuf() to use tcp_packets_in_flight()

tcp_should_expand_sndbuf() does not expand the send buffer if we have
filled the congestion window.

However, it should use tcp_packets_in_flight() instead of
tp->packets_out to make this check.

Testing has established that the difference matters a lot if there are
many SACKed packets, causing a needless performance shortfall.

Signed-off-by: Neal Cardwell <58d301c70203188c35d379474c26c9cc0636a189@google.com>
Signed-off-by: Yuchung Cheng <5b5a0a360fa35167ac197fe6359c229fde284cf2@google.com>
Signed-off-by: Eric Dumazet <312c7d941f03386814be517ffdb3e0eb6624e275@google.com>
Signed-off-by: Nandita Dukkipati <c885339f99dffe2a5f7eb16e264b2978fb0befe2@google.com>
Signed-off-by: David S. Miller <fe08d3c717adf2ae63592e4c9aec6e3e404d8e3e@davemloft.net>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs