Remove extern crate statements (#3310)

src/platform_impl/linux/x11/util/hint.rs

@@ -1,5 +1,8 @@
 use std::sync::Arc;
 
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
+
 use super::*;
 
 #[derive(Debug)]

src/platform_impl/linux/x11/util/input.rs

@@ -45,7 +45,7 @@ impl XConnection {
             self.flush_requests()?;
             Ok(true)
         } else {
-            error!("Could not select XKB events: The XKB extension is not initialized!");
+            log::error!("Could not select XKB events: The XKB extension is not initialized!");
             Ok(false)
         }
     }

src/platform_impl/linux/x11/util/randr.rs

@@ -4,6 +4,7 @@ use super::*;
 use crate::platform_impl::platform::x11::monitor;
 use crate::{dpi::validate_scale_factor, platform_impl::platform::x11::VideoMode};
 
+use log::warn;
 use x11rb::protocol::randr::{self, ConnectionExt as _};
 
 /// Represents values of `WINIT_HIDPI_FACTOR`.