kernel/svc: Move and correct returned error code for invalid thread priorities in SetThreadPriority()

All priority checks are supposed to occur before checking the validity
of the thread handle, we're also not supposed to return
ERR_NOT_AUTHORIZED here.

src/core/hle/kernel/svc.cpp

@@ -594,16 +594,17 @@ static ResultCode SetThreadPriority(Handle handle, u32 priority) {
     }
 
     const auto* const current_process = Core::CurrentProcess();
-    SharedPtr<Thread> thread = current_process->GetHandleTable().Get<Thread>(handle);
-    if (!thread) {
-        return ERR_INVALID_HANDLE;
-    }
 
     // Note: The kernel uses the current process's resource limit instead of
     // the one from the thread owner's resource limit.
     const ResourceLimit& resource_limit = current_process->GetResourceLimit();
     if (resource_limit.GetMaxResourceValue(ResourceType::Priority) > priority) {
-        return ERR_NOT_AUTHORIZED;
+        return ERR_INVALID_THREAD_PRIORITY;
+    }
+
+    SharedPtr<Thread> thread = current_process->GetHandleTable().Get<Thread>(handle);
+    if (!thread) {
+        return ERR_INVALID_HANDLE;
     }
 
     thread->SetPriority(priority);