fix: incorrect check on fast moe activation (#544)

Signed-off-by: Mehant Kammakomati <[email protected]>

Author: kmehant

tuning/sft_trainer.py

@@ -167,7 +167,8 @@ def train(
                 "`--padding_free` argument was called with `packing=True`, "
                 "Trainer should not perform packing when using `--padding_free`"
             )
-
+    if fast_moe_config is not None and fast_moe_config.fast_moe is None:
+        fast_moe_config = None
     if fast_moe_config is not None:
         # Checking for unsupported modules with Scatter MoE for LoRA
         # Only raise an error for `all-linear`