cpu: Remove an unused variable from one of the branch predictors.
cpu: Remove an unused variable from one of the branch predictors.

The variable upsets clang and breaks the build.

Change-Id: Ia2315e1753b6e9e701bf18eadf8cf448643577b4
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/57172
Maintainer: Gabe Black <d3e8afea784ab4a50a2dbf9149d2eaa8478e1cbc@gmail.com>
Reviewed-by: Daniel Carvalho <91779fc734d358d9575ec4910de29bfcbcaf1b22@yahoo.com.br>
Tested-by: kokoro <2ac7b1f3fa578934c95181d4272be0d3bca00121@google.com>

gem5/gem5,gem5/gem5,gem5/gem5,gem5/gem5,gem5/gem5,gem5/gem5,gem5/gem5