remove churn_output() function and calls to it.

remove churn_output() function and calls to it.
when SSL needs to flush (e.g. during SSL_accept()) it will call BIO_flush()
which will trigger a call to bio_bucket_ctrl() -> BIO_bucket_flush().
so we only need to flush the output ourselves if we receive an EOS or
FLUSH bucket.

BIO_bucket_flush() and churn_output() had been turning up near the top
of the profile with gprof.  churn_output() of course has now vanished
and BIO_bucket_flush() has dropped, being called far less than before.

PR:
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git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@92271 13f79535-47bb-0310-9956-ffa450edef68