C++ does not have automatic casting to/from void pointers, so need
explicit cast if header is to be included in C++ code
Fixes: f901d9c82688 ("ipsec: add helpers to group completed crypto-ops")
Cc: stable@dpdk.org
Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
Acked-by: Konstantin Ananyev <konstantin.ananyev@intel.com>