crypto/engine/eng_devcrypto.c: ensure we don't leak resources

If engine building fails for some reason, we must make sure to close
the /dev/crypto handle.

Reviewed-by: Bernd Edlinger <bernd.edlinger@hotmail.de>
(Merged from https://github.com/openssl/openssl/pull/7506)

(cherry picked from commit 681e8cac)