Fix mouse-key spamming empty reports (#21663)

Problem:

`mousekey_task` spams empty hid reports with when a mouse key is
pressed, causing resource exhaustion in the USB mouse endpoint.

Cause:

The check whether or not to send a new mouse report would always
evaluate to true if a mouse key is pressed:

1. `mouse_report` has non-zero fields and `tmpmr` is a copy of this
   fields.
2. `mouse_report` is set to zero, `tmpmr` has now non-zero fields.
3. `has_mouse_report_changed` compares the two and evaluates to true
4. a mouse report is sent.

Fix:

The check condition of `has_mouse_report_changed` will evaluate any
empty record as unchanged, as mouse report data is relative and doesn't
need to return to zero. An empty report will still be send by
`register_mouse` on release of all mouse buttons.

0 files changed, 0 insertions, 0 deletions