src: rename sun -> s redux

Like commit 05fccae but for another call site.  Overlooked in the
previous change, mea culpa.
src: fix use after free

The memory of the uv_poll_t handle was freed without the handle being
closed first.  As a result, it was still referenced internally by libuv,
leading to spurious segmentation faults.  This looks like an oversight
in the switch from libev to libuv in commit 04dd6d7.

You'd think _I_ of all people would know better, wouldn't you?

Fixes #8.