Fix issue 22 incorrect filling computation time into the msg_size

[dageita]

Fixed the issue of msg_size being overwritten by _ elapsed_time in the generated workload code
#22

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[Huoyuan100861]

Fixed the issue of msg_size being overwritten by _ elapsed_time in the generated workload code #22

I understand the intent of your modification, but it could lead to unexpected impacts on the output. We are currently double-checking.