Remove redundant tests
Remove redundant tests

Removed the three checks of type against NULL since type cannot be NULL for
any of them.

Moved a check of ->engine inside a CPP guard for engines.

Didn't address the teardown and rebuild of the provider context.

Partially fixes #16947

Reviewed-by: Tomas Mraz <2bc6038c3dfca09b2da23c8b6da8ba884dc2dcc2@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/16952)

openssl/openssl,openssl/openssl,openssl/openssl,openssl/openssl,openssl/openssl,openssl/openssl