speed.c: simplify aggregation of ecdh --multi results
speed.c: simplify aggregation of ecdh --multi results

CLA: trivial

Signed-off-by: Cristian Stoica <cristian.stoica@nxp.com>

Reviewed-by: Geoff Thorpe <c3918f39022407dee6a0056ceca9b1aa80e8e4ce@openssl.org>
Reviewed-by: Richard Levitte <5fb523282dd7956571c80524edc2dccfa0bd8234@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1377)
openssl/openssl,openssl/openssl,openssl/openssl,openssl/openssl,openssl/openssl,openssl/openssl