Fix additional leaks in #22103 tests

test_options_validate_impl() incorrectly executed subsequent phases of
config parsing and validation after an expected error.  This caused
msg to leak when those later phases (which would likely produce errors
as well) overwrote it.

src/test/test_options.c

@@ -187,6 +187,8 @@ test_options_validate_impl(const char *configuration,
       goto done;
   }
   tt_int_op((r == 0), OP_EQ, (msg == NULL));
+  if (r)
+    goto done;
 
   r = config_assign(&options_format, opt, cl, 0, &msg);
   if (phase == PH_ASSIGN) {
@@ -196,6 +198,8 @@ test_options_validate_impl(const char *configuration,
       goto done;
   }
   tt_int_op((r == 0), OP_EQ, (msg == NULL));
+  if (r)
+    goto done;
 
   r = options_validate(NULL, opt, dflt, 0, &msg);
   if (phase == PH_VALIDATE) {