container/commit: Actually return an error code

[cgwalters]

I ended up rewriting a lot of this so we could more properly unit test it. But the problem here boils down to move || having moved the error counter into the closure, but since it's copy it made a new copy.

[cgwalters]

I actually did this minimal fix first:

diff --git a/lib/src/commit.rs b/lib/src/commit.rs
index 3f30842..51cd977 100644
--- a/lib/src/commit.rs
+++ b/lib/src/commit.rs
@@ -39,15 +39,15 @@ pub(crate) async fn container_commit() -> Result<()> {
     println!("Checking /var for files");
     let var_path = Path::new("/var");
 
-    let mut error_count = 0;
-
     task::spawn_blocking(move || -> Result<()> {
-        validate_directories_only(var_path, &mut error_count)
+        let mut error_count = 0;
+        validate_directories_only(var_path, &mut error_count)?;
+        if error_count != 0 {
+            anyhow::bail!("Found content in /var");
+        }
+        Ok(())
     })
     .await??;
 
-    if error_count != 0 {
-        anyhow::bail!("Found content in /var");
-    }
     Ok(())
 }

but the desire to unit test this drove a larger rework.

[jmarrero]

lgtm