rtp: Cosmetic cleanup

Remove leftover debug comments, fix brace placement and
add whitespace, remove unnecessary and weirdly placed braces.

Signed-off-by: Martin Storsjö <martin@martin.st>
rtp: Rename a static variable to normal naming conventions

Signed-off-by: Martin Storsjö <martin@martin.st>
rtsp: Remove references to weirdly named variables in other files

One of them is renamed now, but mentioning it by name serves
no purpose here.  The other table mentioned ceased to exist
under that name in 4934884a1 in 2006.

Signed-off-by: Martin Storsjö <martin@martin.st>
rtsp: Remove an outdated comment

It is unclear what the bug exactly was and if it ever was fixed,
and we don't even support decoding via faad any longer. The
comment has been present since d0deedcb in 2006.

Signed-off-by: Martin Storsjö <martin@martin.st>
rtpdec: Remove a useless todo comment

The question can be answered: No, we do not know the initial sequence
number from the SDP. In certain cases, it can be known from the
RTP-Info response header in RTSP though. (In that case, we use it as
timestamp origin, but not for rtp receiver statistics.)

Signed-off-by: Martin Storsjö <martin@martin.st>