TL/CUDA: fix oob_req leak and double-free in NVLS init cleanup

Two bugs in the BARRIER state error path and cleanup section:

1. When req_test returns a negative status (barrier failure), team->oob_req
   was freed via barrier_data path but req_free was never called, leaking
   the OOB transport request handle.  Add req_free + NULL the pointer before
   goto cleanup.

2. nvls->mc_va, nvls->uc_va, and nvls->mc_memhandle are stored at the end
   of STATE_ADD_DEVICE before falling through to STATE_BARRIER.  If the
   barrier then fails and jumps to cleanup, the cleanup block frees these
   resources via local variables but leaves the nvls struct fields non-NULL.
   A subsequent ucc_tl_cuda_nvls_destroy call then unmaps/releases them
   again causing a double-free / CUDA resource corruption.  Zero the nvls
   fields immediately after the local-variable cleanup blocks.

Author: ikryukov

src/components/tl/cuda/tl_cuda_nvls.c

@@ -695,6 +695,8 @@ ucc_status_t ucc_tl_cuda_nvls_init(
         }
         if (status < 0) {
             tl_error(UCC_TL_TEAM_LIB(team), "NVLS barrier failed");
+            team->oob.req_free(team->oob_req);
+            team->oob_req = NULL;
             ucc_free(nvls->barrier_data);
             nvls->barrier_data = NULL;
             goto cleanup;
@@ -738,6 +740,7 @@ ucc_status_t ucc_tl_cuda_nvls_init(
             tl_error(UCC_TL_TEAM_LIB(team),
                      "failed to free mc_va during cleanup");
         }
+        nvls->mc_va = 0;
     }
 
     // Unmap and free unicast VA if it was reserved/mapped
@@ -750,6 +753,7 @@ ucc_status_t ucc_tl_cuda_nvls_init(
             tl_error(UCC_TL_TEAM_LIB(team),
                      "failed to free uc_va during cleanup");
         }
+        nvls->uc_va = 0;
     }
 
     // Release memory handle if it was created
@@ -758,6 +762,7 @@ ucc_status_t ucc_tl_cuda_nvls_init(
             tl_error(UCC_TL_TEAM_LIB(team),
                      "failed to release mem_handle during cleanup");
         }
+        nvls->mc_memhandle = 0;
     }
 
     // Release multicast handle if it was created or imported