Fix -Wformat issues from #8612

Built locally with -Wformat -Werror=format on a recent version of clang. (Apparently, clang12 which we use on CI is not new enough?)


ghstack-source-id: d676877
ghstack-comment-id: 2940815253
Pull-Request-resolved: #11360

Author: swolchok

runtime/core/exec_aten/testing_util/tensor_factory.h

@@ -624,8 +624,8 @@ inline void validate_strides(
       if ((strides[i] == strides[j])) {
         ET_CHECK_MSG(
             false,
-            "Stride value and size dont comply at index %d."
-            " strides[%d]: %d, strides[%d] = %d, sizes[%d] = %d, sizes[%d] = %d",
+            "Stride value and size dont comply at index %lu."
+            " strides[%lu]: %d, strides[%d] = %d, sizes[%lu] = %d, sizes[%d] = %d",
             i,
             i,
             strides[i],