msm: camera: Fix couple of error cases.

- Currently we initialize the vb2 queue during
  set_format and release it during msm_close.
  This might cause problems if the application
  is doing resolution changes in the same camera
  instance, where there can be multiple formats
  within the single instance. So release the vb2
  queue when the application is unregistering
  the buffers and toggle initialized flag so that
  the vb2 queue is initialized again when the new
  format is set.
- Also, display an error and return immediately
  without queueing the buffer, if the application
  erroneously queues a buffer after unregistering
  all the buffers.

Change-Id: I1236d933991f5650b4982c8db715fd0fd81b53cd
Signed-off-by: Kiran Kumar H N <hurlisal@codeaurora.org>
CRs-Fixed: 317429