cortex-m-semihosting: hprint! family of macros do not format strings without arguments

[suaviloquence]

In the hprint! macros:

cortex-m/cortex-m-semihosting/src/macros.rs

Lines 36 to 44 in f2fc7d3

	#[macro_export]
	macro_rules! hprint {
	($s:expr) => {
	$crate::export::hstdout_str($s)
	};
	($($tt:tt)*) => {
	$crate::export::hstdout_fmt(format_args!($($tt)*))
	};
	}

They do not print format strings with no arguments (e.g., hprint!("{address}") is sugar for hprint!("{}", address), which is a deviation from the stdlib print! macros using format_args!.

If it's acceptable performance-wise, I can submit a PR to use e.g. hstdout_fmt in this case instead of hstdout_str, otherwise I can document this deviation.

[BartMassey]

I would love to see the macros use hstdout_fmt in all cases; I don't think the performance matters given that it's semihosting anyway.