fix style

Signed-off-by: Ziy1-Tan <[email protected]>

vmm/task/src/main.rs

@@ -18,6 +18,7 @@ limitations under the License.
 
 use std::{collections::HashMap, convert::TryFrom, path::Path, process::exit, sync::Arc};
 
+use anyhow::anyhow;
 use containerd_shim::{
     asynchronous::{monitor::monitor_notify_by_pid, util::asyncify},
     error::Error,
@@ -187,8 +188,12 @@ fn init_logger(log_level: &str, enable_tracing: bool) -> anyhow::Result<()> {
     }
 
     let subscriber = Registry::default().with(env_filter).with(layers);
-    tracing::subscriber::set_global_default(subscriber).expect("unable to set global subscriber");
-
+    match tracing::subscriber::set_global_default(subscriber) {
+        Ok(_) => {}
+        Err(e) => {
+            return Err(anyhow!("failed to set global default subscriber: {}", e));
+        }
+    }
     Ok(())
 }