soc: qcom: hab: unify variable type to avoid implicit conversion

correcting the type of sizebytes and total_size to size_t,it can avoid
implicit conversion which maybe cause some unknown issue.

Change-Id: I1c1cc9e92ca2920cc49685edef0d928dd67454c7
Signed-off-by: Yao Jiang <yaojia@codeaurora.org>