Fix compile error: Make IOV live longer

[vars1ty]

Fixes a compile error that I ran into today after running cargo update, where it complains that io::IoSliceMut::new(&mut input_buffer)] doesn't live long enough, so I moved it into its own mutable variable, named "iov" to solve it.

[lemunozm]

Thanks! There are some clippy errors by lines automatically changed by your IDE, once you fix them, I merge them 😃

[lemunozm]

@vars1ty could you fix the clippy issues in order to merge it?