fmt: fix typo in errors.go

Fixes #32802

Change-Id: I756ca49285130b45777bd29de440db296d9632e9
Reviewed-on: https://go-review.googlesource.com/c/go/+/184057
Run-TryBot: Baokun Lee <nototon@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>

src/fmt/errors.go

@@ -12,7 +12,7 @@ import "errors"
 // If the format specifier includes a %w verb with an error operand,
 // the returned error will implement an Unwrap method returning the operand. It is
 // invalid to include more than one %w verb or to supply it with an operand
-// that does not implement the error innterface. The %w verb is otherwise
+// that does not implement the error interface. The %w verb is otherwise
 // a synonym for %v.
 func Errorf(format string, a ...interface{}) error {
 	p := newPrinter()