fix(serde): Rename visit_struct_key to visit_struct_field

This is more consistent with the rest of the serde naming patterns.

serde/src/de/mod.rs

@@ -407,7 +407,7 @@ pub trait Deserializer {
     /// This allows deserializers to choose between &str, usize, or &[u8] to properly deserialize a
     /// struct key.
     #[inline]
-    fn visit_struct_key<V>(&mut self, visitor: V) -> Result<V::Value, Self::Error>
+    fn visit_struct_field<V>(&mut self, visitor: V) -> Result<V::Value, Self::Error>
         where V: Visitor,
     {
         self.visit(visitor)

serde_codegen/src/de.rs

@@ -917,7 +917,7 @@ fn deserialize_field_visitor(
                     }
                 }
 
-                deserializer.visit_struct_key(__FieldVisitor::<D>{ phantom: PhantomData })
+                deserializer.visit_struct_field(__FieldVisitor::<D>{ phantom: PhantomData })
             }
         }
     ).unwrap();