Fix clippy warnings

src/row.rs

@@ -156,7 +156,7 @@ where
         self.rows
             .next()
             .transpose()
-            .map(|row_result| row_result.and_then(|row| (map)(&row)))
+            .map(|row_result| row_result.and_then(|row| (map)(row)))
     }
 }
 
@@ -181,7 +181,7 @@ where
         self.rows
             .next()
             .transpose()
-            .map(|row_result| row_result.map_err(E::from).and_then(|row| (map)(&row)))
+            .map(|row_result| row_result.map_err(E::from).and_then(|row| (map)(row)))
     }
 }
 
@@ -210,7 +210,7 @@ impl<'stmt> FallibleStreamingIterator for Rows<'stmt> {
     #[inline]
     fn advance(&mut self) -> Result<()> {
         match self.stmt {
-            Some(ref stmt) => match stmt.step() {
+            Some(stmt) => match stmt.step() {
                 Ok(true) => {
                     self.row = Some(Row { stmt });
                     Ok(())