Merge pull request #795 from weisy11/develop_reg

fix bug

ppcls/arch/gears/identity_head.py

+from paddle import nn
+
+
 class IdentityHead(nn.Layer):
     def __init__(self):
         super(IdentityHead, self).__init__()
 
     def forward(self, x, label=None):
-        return {"features": x, "logits": None}
\ No newline at end of file
+        return {"features": x, "logits": None}