CC3XX: Fix -Wmaybe-uninitialized build warning

Fix warning: 'cc_err' may be used uninitialized when
CC312_LEGACY_DRIVER_API_ENABLED is OFF.

Signed-off-by: Summer Qin <summer.qin@arm.com>
Change-Id: I8ea40468b4a1c264a0a90bc834cbb774a9e2acab
1 file changed