msm: camera: jpeg: Protect ref_cnt underrun and other error

During release, check if ref_cnt is already zero to prevent
unbalanced deinit. Also, while handling errors during acquire,
need to rectify the ref_cnt to prevent inconsistency.

Change-Id: I7c53b19d0e43e04d8b497284a1c80b60f048eeac
Signed-off-by: Harsh Shah <harshs@codeaurora.org>