[LINTER] Enforce using C++ style for void parameters

Summary:
This is a follow up from D3725 and should avoid introducing regressions
(see D3953). This diff also fixes the leftovers from D3725.

Test Plan:
Should return nothing.

arc lint --everything

Edit src/key.h to change to line:

void ECC_Start();

to:

void ECC_Start(void);

Then run:

arc lint

and check the linter offers a fix.

Reviewers: #bitcoin_abc, deadalnix, jasonbcox

Reviewed By: #bitcoin_abc, jasonbcox

Differential Revision: https://reviews.bitcoinabc.org/D3984