Delete target directory before running odrefresh

This allows it to re-create the directory and files when it runs.

Bug: 210460516
Test: composd_cmd async-odrefresh
Change-Id: I1e5a100f0d68d0266c9af9d681e243dd5bdb0556
diff --git a/compos/src/artifact_signer.rs b/compos/src/artifact_signer.rs
index ce32d6b..a4b47d6 100644
--- a/compos/src/artifact_signer.rs
+++ b/compos/src/artifact_signer.rs
@@ -70,13 +70,15 @@
 
         let signature = signer.sign(&bytes)?;
 
-        let mut file = File::create(info_path)?;
+        let mut file =
+            File::create(info_path).with_context(|| format!("Creating {}", info_path.display()))?;
         file.write_all(&bytes)?;
 
         let mut signature_name = info_path.file_name().unwrap().to_owned();
         signature_name.push(SIGNATURE_EXTENSION);
         let signature_path = info_path.with_file_name(&signature_name);
-        let mut signature_file = File::create(&signature_path)?;
+        let mut signature_file = File::create(&signature_path)
+            .with_context(|| format!("Creating {}", signature_path.display()))?;
         signature_file.write_all(&signature)?;
 
         Ok(())