fix missing comma in activation benchmarks (#35104)

Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/35104

I missed this in https://github.com/pytorch/pytorch/pull/34959
after a rebase, fixing.

Test Plan:
running benchmarks no longer crashes
CI

Imported from OSS

Differential Revision: D20560908

fbshipit-source-id: a5494e23953d3c9007e9874d673896291b5322e0
diff --git a/benchmarks/operator_benchmark/pt/qactivation_test.py b/benchmarks/operator_benchmark/pt/qactivation_test.py
index 3c57abd..b2795b3 100644
--- a/benchmarks/operator_benchmark/pt/qactivation_test.py
+++ b/benchmarks/operator_benchmark/pt/qactivation_test.py
@@ -45,7 +45,7 @@
         ('relu', nnq.ReLU),
         ('relu6', nnq.ReLU6),
         ('functional.hardtanh', nnq.functional.hardtanh),
-        ('functional.elu', nnq.functional.elu)
+        ('functional.elu', nnq.functional.elu),
         ('functional.hardsigmoid', nnq.functional.hardsigmoid),
     ),
     attr_names=('op_name', 'op_func'),