goto_programt::output: add missing newline

Author: kroening

regression/goto-instrument/inline_04/test.desc

@@ -4,9 +4,9 @@ main.c
 ^EXIT=0$
 ^SIGNAL=0$
 ^VERIFICATION SUCCESSFUL$
-g[\(].*[\)]$
-h[\(].*[\)]$
+ g[\(].*[\)]$
+ h[\(].*[\)]$
 --
-f[\(].*[\)]$
-other_func[\(].*[\)]$
+ f[\(].*[\)]$
+ other_func[\(].*[\)]$
 ^warning: ignoring

src/goto-programs/goto_program.cpp

@@ -129,7 +129,7 @@ std::ostream &goto_programt::output_instruction(
       // fallthrough
     }
 
-    out << "OTHER " << format(instruction.get_other());
+    out << "OTHER " << format(instruction.get_other()) << '\n';
     break;
 
   case SET_RETURN_VALUE: