Log messages to the serial atomically and rename arch::serial

Co-authored-by: Chuandong Li <lichuand@pku.edu.cn>

kernel/aster-nix/src/console.rs

@@ -18,6 +18,7 @@ impl Write for VirtioConsolesPrinter {
     }
 }
 
+/// Prints the formatted arguments to the standard output.
 pub fn _print(args: Arguments) {
     VirtioConsolesPrinter.write_fmt(args).unwrap();
 }

kernel/aster-nix/src/device/tty/driver.rs

@@ -2,7 +2,6 @@
 
 #![allow(dead_code)]
 
-pub use ostd::arch::console;
 use ostd::mm::VmReader;
 use spin::Once;