Fix broken check for insufficient GPUs

Thanks to @tsjohnso for catching!

Author: njhill

server/text_generation_server/inference_engine/engine.py

@@ -22,9 +22,8 @@ def __init__(self, model_path: str, model_config: Optional[Any]) -> None:
         if torch.cuda.is_available():
             gpu_count = torch.cuda.device_count()
             assert (
-                self.world_size <= gpu_count,
-                f"{self.world_size} shards configured but only {gpu_count} GPUs detected"
-            )
+                self.world_size <= gpu_count
+            ), f"{self.world_size} shards configured but only {gpu_count} GPUs detected"
             device_index = self.rank % torch.cuda.device_count()
             torch.cuda.set_device(device_index)
             self.device = torch.device("cuda", device_index)