remove unused variable external_symbols

Win/lib.icl

@@ -45,8 +45,6 @@ read_external_symbol_names_from_xcoff_file file_name files
 
 	#! (n_external_symbols, external_def_symbols, external_ref_symbols)
 		= extract_external_symbols 0 0 [] [] symbol_table_string string_table;
-	#! external_symbols
-		= external_def_symbols ++ external_ref_symbols;
 		
 	#! ((ok, xcoff_size),files)
 		= FFileSize file_name files;