cast_possible_truncation warning message incorrect

[isaacg1]

The warning message of cast_possible_truncation incorrectly refers to cast_precision_loss.

Example code:

#[warn(clippy::cast_possible_truncation)]
#[allow(clippy::cast_precision_loss)]
fn main() {
    let x: u16 = 0;
    println!("{}", x as u8);
}

The warning message contains the line:

  = help: if this is intentional allow the lint with `#[allow(clippy::cast_precision_loss)]` ...

This message is produced by this line of code:

rust-clippy/clippy_lints/src/casts/cast_possible_truncation.rs

Line 171 in 0f75581

diag.help("if this is intentional allow the lint with `#[allow(clippy::cast_precision_loss)]` ...");