Fix clippy lint about looping over iter()

serde/src/ser/impls.rs

@@ -157,7 +157,7 @@ impl<T> Serialize for [T]
         where S: Serializer,
     {
         let mut state = try!(serializer.serialize_seq(Some(self.len())));
-        for e in self.iter() {
+        for e in self {
             try!(serializer.serialize_seq_elt(&mut state, e));
         }
         serializer.serialize_seq_end(state)
@@ -174,7 +174,7 @@ macro_rules! array_impls {
                 where S: Serializer,
             {
                 let mut state = try!(serializer.serialize_seq_fixed_size($len));
-                for e in self.iter() {
+                for e in self {
                     try!(serializer.serialize_seq_elt(&mut state, e));
                 }
                 serializer.serialize_seq_end(state)

serde_codegen/src/ser.rs

@@ -382,7 +382,7 @@ fn serialize_variant(
         }
         Style::Struct => {
             let mut pat = builder.pat().struct_().id(type_ident).id(variant_ident).build();
-            for field in variant.fields.iter() {
+            for field in &variant.fields {
                 let name = match field.ident {
                     Some(name) => name,
                     None => cx.span_bug(field.span, "struct variant has unnamed fields"),