[TCP] BIC: remove low utilization code.

The latest BICTCP patch at:
http://www.csc.ncsu.edu:8080/faculty/rhee/export/bitcp/index_files/Page546.htm



disables the low_utilization feature of BICTCP because it doesn't work
in some cases. This patch removes it.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>