test/params_test.c: make construct_api_params() static
test/params_test.c: make construct_api_params() static

With enough warning flags, compilers complain when a non-static
function hasn't been properly declared...

Reviewed-by: Nicola Tuveri <5a38b4ac03c90be61ead22c1d11b6e9f49425984@gmail.com>
(Merged from https://github.com/openssl/openssl/pull/8469)

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