Fix coding style nits.

uint32_t parameters don't need to be passed by reference. The
VCMJitterBuffer destructor doesn't need to be virtual because the
class has no virtual methods.

R=stefan@webrtc.org
BUG=none

Review URL: https://webrtc-codereview.appspot.com/55499004

Cr-Commit-Position: refs/heads/master@{#9288}
1 file changed