tests: Migrate InvalidDSUpdateStruct to parameter_validation

Wrong sType is caught by parameter validation so migrate the error
message for InvalidDSUpdateStruct test to match parameter_validation.
This is in preparation for removing a redundant check from
core_validation.
diff --git a/tests/layer_validation_tests.cpp b/tests/layer_validation_tests.cpp
index 040560f..158806f 100644
--- a/tests/layer_validation_tests.cpp
+++ b/tests/layer_validation_tests.cpp
@@ -6925,7 +6925,7 @@
     VkResult err;
 
     m_errorMonitor->SetDesiredFailureMsg(VK_DEBUG_REPORT_ERROR_BIT_EXT,
-                                         "Unexpected UPDATE struct of type ");
+                                         ".sType must be VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET");
 
     ASSERT_NO_FATAL_FAILURE(InitState());