[Bugfix] Fix early return in CustomDeepseekV2MoE.forward during profile_run (#682)

### What this PR does / why we need it?

Fix #674 to avoild KVCache overallocation and OOM risks.

### Does this PR introduce _any_ user-facing change?

No

### How was this patch tested?

Signed-off-by: ApsarasX <apsarax@outlook.com>

Author: ApsarasX

vllm_ascend/models/deepseek_v2.py

@@ -143,24 +143,24 @@ def forward(self, hidden_states: torch.Tensor) -> torch.Tensor:
         attn_metadata = get_forward_context().attn_metadata
         if attn_metadata is None:
             # for profile run
-            return hidden_states
+            is_prefill = True
+        else:
+            is_prefill = attn_metadata.num_prefills > 0
         num_tokens, hidden_dim = hidden_states.shape
         hidden_states = hidden_states.view(-1, hidden_dim)
 
         if self.n_shared_experts is not None:
             shared_output = self.shared_experts(hidden_states)
 
-        if (self.tp_size > 1 and self.enable_mc2
-                and attn_metadata.num_prefills == 0):
+        if (self.tp_size > 1 and self.enable_mc2 and not is_prefill):
             chunks = torch.chunk(hidden_states,
                                  get_tp_group().world_size,
                                  dim=0)
             hidden_states = chunks[get_tp_group().rank_in_group]
 
         # router_logits: (num_tokens, n_experts)
         router_logits, _ = self.gate(hidden_states)
-        is_prefill = True if attn_metadata.num_prefills > 0 else False
-        # is_prefill = attn_metadata.num_prefills > 0
+
         final_hidden_states = self.experts(
             hidden_states=hidden_states,
             router_logits=router_logits,