std: Small cleanup and test improvement

This weeds out a bunch of warnings building stdtest on windows, and it also adds
a check! macro to the io::fs tests to help diagnose errors that are cropping up
on windows platforms as well.

cc #12516

1 files changed, 2 insertions, 2 deletions

diff --git a/src/libstd/path/windows.rs b/src/libstd/path/windows.rs
index 8902ab2edd7..10834aec64c 100644
--- a/src/libstd/path/windows.rs
+++ b/src/libstd/path/windows.rs
@@ -1433,8 +1433,8 @@ mod tests {
         macro_rules! t(
             (s: $path:expr, $join:expr) => (
                 {
-                    let path = ($path);
-                    let join = ($join);
+                    let path = $path;
+                    let join = $join;
                     let mut p1 = Path::new(path);
                     let p2 = p1.clone();
                     p1.push(join);