ext/openssl: Use zend_result return type instead of int where applicable

[Girgias]

Saw this from the recent commit.

Also the one call to php_openssl_load_rand_file and php_openssl_write_rand_file do not check for the return value. Not sure if this is a problem or not?

[bukka]

Also the one call to php_openssl_load_rand_file and php_openssl_write_rand_file do not check for the return value. Not sure if this is a problem or not?

They should be checked and return early.