psa-crypto: fix UNINIT defects reported by Coverity

Initialize variables at declaration to assist Coverity analysis

Coverity does not detect that the serialization functions initialize
these variables. While no issue is being fixed, initializing variables
at declaration improves clarity and helps static analysis tools.

Signed-off-by: Alexandre Gonzalo <alexandre.gonzalo@arm.com>
Change-Id: Ibae8811b80be65fe45c9a97aa69bc329d3c02fe0
6 files changed