Fix doc-comment file references left stale by today's six module splits

~17 comments across the codebase still pointed at udev.rs/winit.rs/
state.rs by their old flat-file names after those became udev/,
winit/, state/ directories - found while auditing what this work
rushed, since the split verification (function/struct-name diffing,
full test suite) checked structural correctness but never comment
accuracy. Updated each to either the specific new file (e.g. "see
state.rs's REPEAT_DELAY" -> "see state/mod.rs's REPEAT_DELAY",
"udev.rs's monitors()" -> "udev/platform.rs's monitors()") or the bare
module name where the reference was already generic ("the udev/winit
backends", not a specific location).

0 files changed, 0 insertions, 0 deletions