ASoC: msm: Fix for a seekbar issue during audio playback.

Issue is that when seek happens several times during audio playback,
and at some point last buffer write done event from DSP is received,
an ioctl drain is issued, which will set pending_buffer flag to 0,
In the mean time before drain finishes a seek comes, which issues
a flush on all the buffers and try to resume the playback again.
Now because the pending_buffer flag is set to 0, CMD_RUN will return
without any further writes to DSP. As a result no audio buffers are
reaching the DSP and hence no audio is getting played.
Make a fix is to set pending_buffer flag to 1 whenever playback is resumed
after seek.

Change-Id: I89812332f14e0682be28445ad1f15564f129ae11
Signed-off-by: Mingming Yin <mingming@codeaurora.org>
msm: vidc: Avoid memset of list elements in the buffer entry.

- Due to race condition between free buffer and flush output buffers,
  invalid buffer is getting accessed sometimes.
- Reset all the members in buffer entry except list elements.

Change-Id: Ia2a3bc4343fc557a6e6d7d9ad93a29a7ab3dfb81
CRs-Fixed: 411197
Signed-off-by: Srinu Gorle <sgorle@codeaurora.org>
(cherry picked from commit 8105df366cf6b9f1ddbc15d561fb6a5f12540416)