Only update the `process_title` struct on success, otherwise it points
to memory libuv doesn't own. Notably, libuv only owns `argv[0]` _after_
copying the argv table.
PR-URL: https://github.com/libuv/libuv/pull/2668
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Santiago Gimeno <santiago.gimeno@gmail.com>