tools/elog-gen: Clean up missing error metadata message

Change-Id: I880cf6793e64db29a6eee74839f5a5bdabb1dff2
Signed-off-by: William A. Kennington III <wak@google.com>
diff --git a/tools/elog-gen.py b/tools/elog-gen.py
index 825fc0f..92abe35 100755
--- a/tools/elog-gen.py
+++ b/tools/elog-gen.py
@@ -221,7 +221,8 @@
                 break
 
         if match is None:
-            print("Error - Did not find name in" + i_elog_meta_yaml)
+            print("Error - Did not find error named %s in %s" % (
+                error['name'], i_elog_meta_yaml))
             continue
 
         error_lvl[fullname] = match.get('level', 'ERR')