Fix possible USM allocation leak

Author: oleksandr-pavlyk

dpctl/tensor/libtensor/include/kernels/sorting/topk.hpp

@@ -475,9 +475,16 @@ sycl::event topk_radix_impl(sycl::queue &exec_q,
     IndexTy *workspace = sycl::malloc_device<IndexTy>(
         padded_total_nelems + total_nelems, exec_q);
 
+    if (nullptr == workspace) {
+        throw std::runtime_error(
+            "Not enough device memory for radix sort topk");
+    }
+
     IndexTy *tmp_tp = sycl::malloc_device<IndexTy>(total_nelems, exec_q);
 
-    if (nullptr == workspace || nullptr == tmp_tp) {
+    if (nullptr == tmp_tp) {
+        using dpctl::tensor::alloc_utils::sycl_free_noexcept;
+        sycl_free_noexcept(workspace, exec_q);
         throw std::runtime_error(
             "Not enough device memory for radix sort topk");
     }