sim: Simplify some struct initializers

In rust, if a struct field is initialized with a variable with the same
name as the field, it is redundant to say `field: field` as the
initializer, and just `field` is sufficient.  Fix the instances of this
that clippy suggests.

Signed-off-by: David Brown <david.brown@linaro.org>
diff --git a/sim/src/tlv.rs b/sim/src/tlv.rs
index 68bfaf7..39bb1b6 100644
--- a/sim/src/tlv.rs
+++ b/sim/src/tlv.rs
@@ -267,7 +267,7 @@
 
     fn add_dependency(&mut self, id: u8, version: &ImageVersion) {
         self.dependencies.push(Dependency {
-            id: id,
+            id,
             version: version.clone(),
         });
     }