intel/tests: Fix coverity warning about possibly leaked memory

If the assert were to fail the memory would leak, which is pretty
harmless in a unit test, but the fix is trivial.

CID: 1635429
Fixes: 6b931a68c7 ("intel/common: Implement Xe KMD in mi_builder tests")
Reviewed-by: Caio Oliveira <caio.oliveira@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/32849>

src/intel/common/tests/mi_builder_test.cpp

@@ -337,8 +337,8 @@ mi_builder_test::SetUp()
             break;
          }
       }
-      ASSERT_TRUE(found_engine);
       free(engines_info);
+      ASSERT_TRUE(found_engine);
 
       struct drm_xe_exec_queue_create queue_create = {
          .width          = 1,