Apply clippy suggestions

[ci skip]

glean-core/src/event_database/mod.rs

@@ -13,7 +13,6 @@ use std::path::{Path, PathBuf};
 use std::sync::RwLock;
 
 use serde::{Deserialize, Serialize};
-use serde_json;
 use serde_json::{json, Value as JsonValue};
 
 use crate::CommonMetricData;

glean-core/src/upload/directory.rs

@@ -9,7 +9,6 @@ use std::fs::{self, File};
 use std::io::{BufRead, BufReader};
 use std::path::{Path, PathBuf};
 
-use log;
 use serde_json::Value as JsonValue;
 use uuid::Uuid;
 

glean-core/src/upload/mod.rs

@@ -20,7 +20,6 @@ use std::sync::atomic::{AtomicBool, Ordering};
 use std::sync::{Arc, RwLock, RwLockWriteGuard};
 use std::thread;
 
-use log;
 use serde_json::Value as JsonValue;
 
 use directory::PingDirectoryManager;
@@ -305,7 +304,7 @@ mod test {
         }
 
         // Clear the queue
-        let _ = upload_manager.clear_ping_queue();
+        drop(upload_manager.clear_ping_queue());
 
         // Verify there really isn't any ping in the queue
         assert_eq!(upload_manager.get_upload_task(), PingUploadTask::Done);
@@ -332,7 +331,7 @@ mod test {
             .unwrap();
 
         // Clear the queue
-        let _ = glean.upload_manager.clear_ping_queue();
+        drop(glean.upload_manager.clear_ping_queue());
 
         let upload_task = glean.get_upload_task();
         match upload_task {

glean-core/tests/common/mod.rs

@@ -11,9 +11,7 @@ use std::fs::{read_dir, File};
 use std::io::{BufRead, BufReader};
 use std::path::Path;
 
-use chrono;
 use chrono::offset::TimeZone;
-use iso8601;
 use iso8601::Date::YMD;
 use serde_json::Value as JsonValue;
 

glean-core/tests/ping_maker.rs

@@ -5,8 +5,6 @@
 mod common;
 use crate::common::*;
 
-use iso8601;
-
 use glean_core::metrics::*;
 use glean_core::ping::PingMaker;
 use glean_core::{CommonMetricData, Glean, Lifetime};