Fix rustfmt formatting in cache spill code

Signed-off-by: Quanyi Ma <eli@patch.sh>

Author: genedna

src/internal/pack/cache_object.rs

@@ -183,8 +183,8 @@ impl FileLoadStore for CacheObject {
     }
 
     fn f_save(&self, path: &Path) -> Result<(), io::Error> {
-        let data =
-            rkyv::to_bytes::<RkyvError>(&CacheObjectOnDiskRef::from(self)).map_err(io::Error::other)?;
+        let data = rkyv::to_bytes::<RkyvError>(&CacheObjectOnDiskRef::from(self))
+            .map_err(io::Error::other)?;
         write_bytes_atomically(path, &data)
     }
 }