ctf: make StreamInputPacketIndexEntry not Comparable

ctf: make StreamInputPacketIndexEntry not Comparable

Move the comparator to the StreamInputPacketIndex so that it is not
a true compareTo. This makes sense as compareTo needs to be a true
comparison not a partial compare. If compare returns 0, it should be
equals, not more or less equivalent.

Change-Id: I614c9f7d1eb48ac239abd7921b0fcf60fda76be3
Signed-off-by: Matthew Khouzam <matthew.khouzam@ericsson.com>
Reviewed-on: https://git.eclipse.org/r/40631
Reviewed-by: Hudson CI
Reviewed-by: Alexandre Montplaisir <alexmonthy@voxpopuli.im>