[CTS] Fix image test resource leak

Author: kbenzie

test/conformance/memory/urMemImageCreate.cpp

@@ -185,12 +185,11 @@ TEST_P(urMemImageCreateWithHostPtrFlagsTest, Success) {
                                     &image_format, &image_desc, nullptr,
                                     host_ptr_buffer.ptr()));
 
-    ur_mem_handle_t image_handle = nullptr;
+    uur::raii::Mem image_handle = nullptr;
     ASSERT_SUCCESS(urMemImageCreate(context, getParam(), &image_format,
                                     &image_desc, host_ptr_buffer.ptr(),
-                                    &image_handle));
-    ASSERT_NE(nullptr, image_handle);
-    ASSERT_SUCCESS(urMemRelease(image_handle));
+                                    image_handle.ptr()));
+    ASSERT_NE(nullptr, image_handle.ptr());
 }
 
 TEST_P(urMemImageCreateWithHostPtrFlagsTest, InvalidHostPtr) {