msm: camera: fix signal error for function msm_post_event

Fix msm_post_event timeout error due to signal,
if return ERESTARTSYS, will re-call wait_event_interruptible_timeout.

Change-Id: I37b8f71564528dea1c436769adcead80bbc1ed3a
Signed-off-by: chiz <chiz@codeaurora.org>