[TCP] MTUprobe: Cleanup send queue check (no need to loop)
The original code has striking complexity to perform a query
which can be reduced to a very simple compare.
FIN seqno may be included to write_seq but it should not make
any significant difference here compared to skb->len which was
used previously. One won't end up there with SYN still queued.
Use of write_seq check guarantees that there's a valid skb in
send_head so I removed the extra check.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Acked-by: John Heffner <jheffner@psc.edu> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>