msm: camera: isp: avoid spink lock recursion

Use spink lock only for a required share resource.
Avoid locking too long and lead to potential dead lock.
Also remove some mistake introduced when rebasing.

Change-Id: Ib80fb9719658a7dff816d4388c5cfc3c83f150af
Signed-off-by: Peter Liu <pingchie@codeaurora.org>