fix up comment

Author: steveklabnik

dropshot/src/logging.rs

@@ -357,11 +357,11 @@ mod test {
 
         /**
          * Records that the caller intends to create a directory with relative
-         * path "path" underneath the root directory for this log test.  Returns
-         * a String representing the path to this directory.  This directory
-         * will be removed during teardown.  Directories and files must be
-         * recorded in the order they would be created so that the order can be
-         * reversed at teardown (without needing any kind of recursive removal).
+         * path "path" underneath the root directory for this log test. Returns
+         * the path to this directory. This directory will be removed during
+         * teardown. Directories and files must be recorded in the order they
+         * would be created so that the order can be reversed at teardown
+         * (without needing any kind of recursive removal).
          */
         fn will_create_dir(&mut self, path: &str) -> PathBuf {
             let mut pathbuf = self.directory.clone();
@@ -428,6 +428,10 @@ mod test {
         );
 
         assert!(result.is_err());
+        assert!(result.unwrap_err().to_string().starts_with(&format!(
+            "open log file \"{}\": Is a directory",
+            &path.display()
+        )));
     }
 
     #[test]
@@ -452,6 +456,10 @@ mod test {
         );
 
         assert!(result.is_err());
+        assert!(result.unwrap_err().to_string().starts_with(&format!(
+            "open log file \"{}\": File exists",
+            &path
+        )));
     }
 
     /*