Prior to this change, several of the fs functions checked for
invalid arguments before initializing the fs request. If a
consumer received a UV_EINVAL from one of these functions, and
then called uv_fs_req_cleanup(), the application would crash, as
the pointer being freed was not allocated. This commit makes
sure that all fs functions initialize the request before returning.
Fixes: https://github.com/libuv/libuv/issues/1508
PR-URL: https://github.com/libuv/libuv/pull/1509
Reviewed-By: Bartosz Sosnowski <bartosz@janeasystems.com>
Reviewed-By: Saúl Ibarra Corretgé <saghul@gmail.com>