genpolicy: align state path getter and setter

Before this patch there was a mismatch between the JSON path under which
the state of the rule evaluation is set in comparison to under which
it is retrieved.

This resulted in the behavior that each time the policy was evaluated,
it thought it was the _first_ time the policy was evaluated.
This also means that the consistency check for the `sandbox_name`
was ineffective.

Signed-off-by: Leonard Cohnen <[email protected]>

src/tools/genpolicy/rules.rego

@@ -152,7 +152,8 @@ get_state() = state {
 }
 
 get_state_path(key) = path {
-    path := concat("/", ["", key]) # prepend "/" to key
+    # prepend "/pstate/" to key
+    path := concat("/", ["/pstate", key])
 }
 
 # Helper functions to conditionally concatenate if op is not null