[AMD] Don't request the unused softmax LSE in the AITER diffusion backend (#32926)

Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>
Co-authored-by: YC Yen-Ching Tseng <yctseng@amd.com>

python/sglang/multimodal_gen/runtime/layers/attention/backends/aiter.py

@@ -204,14 +204,14 @@ class AITerImpl(AttentionImpl):
             )
 
         # BF16 path
-        output, _ = aiter.flash_attn_func(
+        output = aiter.flash_attn_func(
             query,
             key,
             value,
             dropout_p=self.dropout_p,
             causal=self.causal,
             return_attn_probs=False,
-            return_lse=True,
+            return_lse=False,
         )
         return output