SQUASHME: Address clippy complaint about Err(_)?

Clippy advised us to use `return Err(_)` instead of `Err(_)?` in the
`check!` macro

Author: kesyog

src/debug.rs

@@ -202,12 +202,12 @@ macro_rules! check {
     ($cond:expr, $error:expr) => {
         if !$cond {
             let error = $error;
-            Err(fail!(
+            return Err(fail!(
                 error,
                 "check failure: `{}`; returned {:?}",
                 stringify!($cond),
                 error,
-            ))?;
+            ));
         }
     };
 }