msm: camera: icp: Change function return value only to report err

Currently hfi_read_message returns a negative value in case of
error otherwise the words read from the queue as return value.
This change passes an input param that is populated with number
of words read from the queue in a given call. The return value
will only report a success or failure.

Change-Id: I6e60c20131735432b2022a06fdef3b1baa29e7cb
Signed-off-by: Karthik Anantha Ram <kartanan@codeaurora.org>