Remove abs() use in PseudoTcp::process.

Squelches a clang 3.5 compile error for using abs() with a long instead
of labs(). Updated affected code to use uint32:s to match the sign of
m_rx_srtt.

BUG=
R=fischman@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/9409004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@5651 4adac7df-926f-26a2-2b94-8c16560cd09d
1 file changed