fix show-json test to expect error from nested mod

One of the show json command tests expected no error when presented with
an invalid configuration in a nested module. Modify the test created in
PR #21569 so that it can still verify there is no panic, but now expect
an error from init.

command/testdata/show-json/nested-modules/modules/more-modules/main.tf

@@ -1,4 +1,4 @@
-variable "misspelled" {
-  default     = "ehllo"
-  descriptoni = "I am a misspelled attribute"
+variable "ok" {
+  default     = "something"
+  description = "description"
 }