mm-video: vidc: delay sending EOS associated with an empty input

When an empty input (of length 0) is queued with EOS, do not
coalesce this buffer with previously enqueued buffer to avoid EOS
getting associated with that buffer.
The client may percieve this as a dropped output frame.

Change-Id: I1eede5b20f16717ee10a7716d6bc1fd28123d1dd
CRs-fixed: 515586
1 file changed