rust: time: Add PartialEq/Eq/PartialOrd/Ord trait to Ktime

Add PartialEq/Eq/PartialOrd/Ord trait to Ktime so two Ktime instances
can be compared to determine whether a timeout is met or not.

Use the derive implements; we directly touch C's ktime_t rather than
using the C's accessors because it is more efficient and we already do
in the existing code (Ktime::sub).

Reviewed-by: Trevor Gross <[email protected]>
Reviewed-by: Alice Ryhl <[email protected]>
Reviewed-by: Gary Guo <[email protected]>
Reviewed-by: Fiona Behrens <[email protected]>
Tested-by: Daniel Almeida <[email protected]>
Reviewed-by: Andreas Hindborg <[email protected]>
Signed-off-by: FUJITA Tomonori <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Andreas Hindborg <[email protected]>

Author: fujita

rust/kernel/time.rs

@@ -29,7 +29,7 @@ pub fn msecs_to_jiffies(msecs: Msecs) -> Jiffies {
 
 /// A Rust wrapper around a `ktime_t`.
 #[repr(transparent)]
-#[derive(Copy, Clone)]
+#[derive(Copy, Clone, PartialEq, PartialOrd, Eq, Ord)]
 pub struct Ktime {
     inner: bindings::ktime_t,
 }