[mlir] Fix syntax example for tensor.from_elements

Parens are not used here

Author: GMNGeoffrey

mlir/include/mlir/Dialect/Tensor/IR/TensorOps.td

@@ -308,7 +308,7 @@ def Tensor_FromElementsOp : Tensor_Op<"from_elements", [
     Example:
 
     ```mlir
-    tensor.from_elements(i_1, ..., i_N) :  tensor<Nxindex>
+    tensor.from_elements i_1, ..., i_N :  tensor<Nxindex>
     ```
   }];