[Ops][Misc] Fix file header and include guard in hc_post_tiling (vllm-project#11298)

### What this PR does / why we need it?
This PR corrects the file header comment in `hc_post_tiling.cpp` and the
`#endif` include guard comment in `hc_post_tiling.h` to match the actual
file names, replacing leftover references to
`gather_selection_kv_cache_tiling`.

- vLLM version: v0.23.0
- vLLM main:
vllm-project/vllm@a30addc
---------
Signed-off-by: Vadim <87440656+KlyzhenkoVadim@users.noreply.github.com>

Author: KlyzhenkoVadim

csrc/moe/hc_post/op_host/hc_post_tiling.cpp

@@ -9,7 +9,7 @@
  */
 
 /*!
- * \file gather_selection_kv_cache_tiling.cpp
+ * \file hc_post_tiling.cpp
  * \brief
  */
 
@@ -228,4 +228,4 @@ IMPL_OP_OPTILING(HcPost)
     .Tiling(Tiling4HcPost)
     .TilingParse<HcPostCompileInfo>(TilingPrepare4HcPost);
 
-} // namespace optiling
+} // namespace optiling

csrc/moe/hc_post/op_host/hc_post_tiling.h

@@ -109,4 +109,4 @@ class HcPostTiling {
 
 } // namespace optiling
 
-#endif // GATHER_SELECTION_KV_CACHE_TILING_H_
+#endif // HC_POST_TILING_H_