fixed a small bug

--- a/src/Pure/Thy/read.ML	Sun Apr 24 11:15:14 1994 +0200
+++ b/src/Pure/Thy/read.ML	Sun Apr 24 11:24:12 1994 +0200
@@ -277,7 +277,7 @@
          (*Remove temporary files*)
          if not (!delete_tmpfiles) orelse (thy_file = "") orelse thy_uptodate 
            then ()
-         else delete_file (out_name name);
+         else delete_file (out_name thy_name);
          delete_file ".tmp.ML"
         )
     end;