put the file name in b3sum error output

This was previously there, but got dropped in
c5c07bb337d0af7522666d05308aaf24eef3709c.

1 files changed, 1 insertions, 1 deletions

diff --git a/b3sum/src/main.rs b/b3sum/src/main.rs
index c799390..b01e5de 100644
--- a/b3sum/src/main.rs
+++ b/b3sum/src/main.rs
@@ -612,7 +612,7 @@ fn main() -> Result<()> {
                 let result = hash_one_input(path, &args);
                 if let Err(e) = result {
                     some_file_failed = true;
-                    eprintln!("{}: {}", NAME, e);
+                    eprintln!("{}: {}: {}", NAME, path.to_string_lossy(), e);
                 }
             }
         }