Fix typo in bench.sh

[vimt]

Which issue does this PR close?

Closes #.

Rationale for this change

Change 1

I meet error when I try to run command ./bench.sh data tpch10_mem as described in usage.

Error: unknown benchmark 'tpch10_mem' for data generation

I think this is due to a typo in usage

Change 2

And when I open bench.sh, IDE tells me that there is an error in the main function.

main references arguments, but none are ever passed.
See SC2120.

The main function is called without passing any arguments, but there is such code BRANCH1=$1 and BRANCH2=$2

What changes are included in this PR?

1. Fix typo
2. Calling compare_benchmarks with parameter passing

Are these changes tested?

I tested it manually with bash -x

Are there any user-facing changes?

No

[alamb]

Thank you @vimt