Fix unused_imports

Author: mkroening

src/arch/x86_64/kernel/pci.rs

@@ -1,3 +1,5 @@
+use num_derive::{FromPrimitive, ToPrimitive};
+
 use crate::arch::x86_64::mm::{PhysAddr, VirtAddr};
 use crate::collections::irqsave;
 use crate::drivers::net::rtl8139::{self, RTL8139Driver};

src/lib.rs

@@ -48,8 +48,6 @@ extern crate alloc;
 extern crate bitflags;
 #[macro_use]
 extern crate log;
-#[macro_use]
-extern crate num_derive;
 #[cfg(not(any(target_os = "none", target_os = "hermit")))]
 #[macro_use]
 extern crate std;