Transition the code to Rust 2018

src/main.rs

@@ -2,12 +2,10 @@
 #![cfg_attr(not(test), no_main)] // disable all Rust-level entry points
 #![cfg_attr(test, allow(dead_code, unused_macros, unused_imports))]
 
-#[macro_use]
-extern crate blog_os;
-extern crate x86_64;
-
 use core::panic::PanicInfo;
 
+use blog_os::println;
+
 /// This function is the entry point, since the linker looks for a function
 /// named `_start` by default.
 #[cfg(not(test))]