Remove some usize

src/error.rs

@@ -456,11 +456,11 @@ impl error::FromError<SslError> for ConnectError {
 #[derive(Clone, PartialEq, Eq, Debug)]
 pub enum ErrorPosition {
     /// A position in the original query
-    Normal(usize),
+    Normal(u32),
     /// A position in an internally generated query
     Internal {
         /// The byte position
-        position: usize,
+        position: u32,
         /// A query generated by the Postgres server
         query: String
     }