cpu: Fix indirect branch history updates

Recent changes to indirect branch predictor interface accesses
non-existent buffers even when indirect predictor is not in use.

Change-Id: I0df9ac4d5f6f3cb63e4d1bd36949c27f7611eef6
Reviewed-on: https://gem5-review.googlesource.com/c/16668
Reviewed-by: Anthony Gutierrez <anthony.gutierrez@amd.com>
Maintainer: Anthony Gutierrez <anthony.gutierrez@amd.com>
1 file changed