New Lint: parameter of function only used in recursive call

[flip1995]

If a parameter of a function is only used in a recursive call of this functions body, it is probably unintended and useless:

fn rec_fn(a: i32) {
    //some conditions, no a... 
    rec_fn(a) 
} 

See also #2622 (comment)

[jamesmcm]

This should be addressed by #8422

[xFrednet]

Thank you for pointing that out @jamesmcm