all: format code according to Go 1.19 rules

Go 1.19 started reformatting code in a way that makes it more obvious
how it will be rendered on pkg.go.dev. It gets it almost right, but not
entirely. Therefore, I had to modify some of the comments so that they
are formatted correctly.

src/machine/usb/hid/keyboard/keycode.go

@@ -5,6 +5,7 @@ type Keycode uint16
 
 // keycode returns the given Unicode codepoint translated to a Keycode sequence.
 // Unicode codepoints greater than U+FFFF are unsupported.
+//
 //go:inline
 func keycode(p uint16) Keycode {
 	if p < 0x80 {