[llvm] [AMDGPU][test] fix the error case in update_mc_test_check script (PR #112731)

[Brox Chen via llvm-commits]

broxigarchen wrote:

> > > Needs a test using the `--llvm-mc-binary` option?
> > 
> > 
> > I am not sure if we can do this in the test here? since it requires a mc-binary location
> 
> When I use `--llvm-mc-binary`, which is my default way of using it, the script changes the `NOTE: Assertions have been autogenerated by ...` line to mention the `--llvm-mc-binary` option. This doesn't happen when I update llc tests.

updated the `--llvm-mc-binary` in common.py

https://github.com/llvm/llvm-project/pull/112731