[llvm] [NVPTX] Fix maybe unused variable in 17852ded (PR #169542)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `clangd-ubuntu-tsan` running on `clangd-ubuntu-clang` while building `llvm` at step 6 "test-build-clangd-clangd-index-server-clangd-in...".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/134/builds/30442

<details>
<summary>Here is the relevant piece of the build log for the reference</summary>

```
Step 6 (test-build-clangd-clangd-index-server-clangd-in...) failure: test (failure)
******************** TEST 'Clangd :: initialize-params.test' FAILED ********************
Exit Code: 66

Command Output (stderr):
--
clangd -lit-test < /vol/worker/clangd-ubuntu-clang/clangd-ubuntu-tsan/llvm-project/clang-tools-extra/clangd/test/initialize-params.test | /vol/worker/clangd-ubuntu-clang/clangd-ubuntu-tsan/build/bin/FileCheck -strict-whitespace /vol/worker/clangd-ubuntu-clang/clangd-ubuntu-tsan/llvm-project/clang-tools-extra/clangd/test/initialize-params.test # RUN: at line 1
+ clangd -lit-test
+ /vol/worker/clangd-ubuntu-clang/clangd-ubuntu-tsan/build/bin/FileCheck -strict-whitespace /vol/worker/clangd-ubuntu-clang/clangd-ubuntu-tsan/llvm-project/clang-tools-extra/clangd/test/initialize-params.test
WARNING: ThreadSanitizer: unexpected memory mapping 0x79fffef72000-0x79ffff400000
FATAL: ThreadSanitizer: unexpectedly found incompatible memory layout.
FATAL: Please file a bug.
I[18:43:00.196] clangd version 22.0.0git (https://github.com/llvm/llvm-project.git 6c8ff4f2bbae6fe29b0ef67edb70e6d73b47beb3)
I[18:43:00.196] Features: linux+debug+tsan+grpc
I[18:43:00.196] PID: 339624
I[18:43:00.196] Working directory: /vol/worker/clangd-ubuntu-clang/clangd-ubuntu-tsan/build/tools/clang/tools/extra/clangd/test
I[18:43:00.196] argv[0]: clangd
I[18:43:00.196] argv[1]: -lit-test
I[18:43:00.196] Starting LSP over stdin/stdout
V[18:43:00.197] <<< {
  "id": 0,
  "jsonrpc": "2.0",
  "method": "initialize",
  "params": {
    "capabilities": {},
    "processId": 123,
    "rootUri": "test:///workspace",
    "trace": "off"
  }
}

I[18:43:00.197] <-- initialize(0)
I[18:43:00.198] --> reply:initialize(0) 1 ms

--

********************


```

</details>

https://github.com/llvm/llvm-project/pull/169542