Fixup opt to reduce the amount of odd if statements. (#2833)

* Fixup opt to reduce the amount of odd if statements.

* Fixing cargo lock

server/text_generation_server/models/custom_modeling/opt_modeling.py

@@ -12,7 +12,8 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
-""" PyTorch OPT model."""
+"""PyTorch OPT model."""
+
 import random
 from typing import List, Optional, Tuple, Union
 
@@ -317,7 +318,6 @@ def __init__(self, layer_id: int, prefix: str, config: OPTConfig, weights):
         super().__init__()
         self.process_group = weights.process_group
         self.hidden_size = config.hidden_size
-        prefix = f"{prefix if prefix else ''}decoder.layers.{layer_id}"
         self.self_attn = OPTAttention(
             config,
             prefix=f"{prefix}.self_attn",
@@ -478,7 +478,12 @@ def __init__(self, prefix: str, config: OPTConfig, weights):
 
         self.layers = nn.ModuleList(
             [
-                OPTDecoderLayer(layer_id, prefix, config, weights)
+                OPTDecoderLayer(
+                    layer_id,
+                    prefix=f"{prefix}decoder.layers.{layer_id}",
+                    config=config,
+                    weights=weights,
+                )
                 for layer_id in range(config.num_hidden_layers)
             ]
         )