fix(lab/4): panic handler

Author: GZTimeWalker

src/0x04/pkg/lib/src/macros.rs

@@ -17,20 +17,20 @@ macro_rules! entry {
 fn panic(info: &core::panic::PanicInfo) -> ! {
     let location = if let Some(location) = info.location() {
         alloc::format!(
-            "{}:{}:{}",
+            "{}@{}:{}",
             location.file(),
             location.line(),
             location.column()
         )
     } else {
         "Unknown location".to_string()
     };
-    let msg = if let Some(msg) = info.message() {
-        alloc::format!("{}", msg)
-    } else {
-        "No more message...".to_string()
-    };
-    errln!("\n\n\rERROR: panicked at {}\n\n\r{}", location, msg);
+
+    errln!(
+        "\n\n\rERROR: panicked at {}\n\n\r{}",
+        location,
+        info.message()
+    );
 
     // FIXME: after syscall, add lib::sys_exit(1);
     loop {}