Hardening FF-A RPC caller

Fix buffer overflow in FF-A RPC calls with large (>~4k) request size.
Add additional error checks. Refactor file to meet checkpatch
requirements.

Signed-off-by: Imre Kis <imre.kis@arm.com>
Change-Id: I5b231cce4a5e79ace074ce9288c176d88b76aaaa
1 file changed