[Bugfix] Fix marlin moe fallback logic for llama4 (#18042)

Signed-off-by: mgoin <mgoin64@gmail.com>

vllm/model_executor/layers/quantization/utils/marlin_utils.py

@@ -171,13 +171,19 @@ def check_moe_marlin_supports_layer(layer: LinearBase, group_size: int) \
                                     -> bool:
     hidden_size = layer.hidden_size
     intermediate_size_per_partition = layer.intermediate_size_per_partition
+    # apply_router_weight_on_input is not supported for moe marlin
+    supports_router_weight = not layer.apply_router_weight_on_input
+    # moe marlin requires the activation to be silu
+    supports_activation = layer.activation == "silu"
 
     # gate-up: (n, k) = (intermediate_size_per_partition * 2, hidden_size)
     # down: (n, k) = (hidden_size, intermediate_size_per_partition)
     # moe marlin requires n % 128 == 0 and k % 64 == 0
-    return hidden_size % 128 == 0 and \
-        intermediate_size_per_partition % max(64, group_size) == 0 and \
-        group_size in [-1, 32, 64, 128]
+    supports_shape = hidden_size % 128 == 0 and \
+        intermediate_size_per_partition % max(64, group_size) == 0
+    supports_group_size = group_size in [-1, 32, 64, 128]
+    return supports_shape and supports_group_size and \
+        supports_router_weight and supports_activation
 
 
 def marlin_make_workspace(output_size_per_partition: int,