KVM: selftests: x86: Sync the new name of the test case to .gitignore

Fixing side effect of the so-called opportunistic change in the commit.

Fixes: dc8a9febbab0 ("KVM: selftests: x86: Fix test failure on arch lbr capable platforms")
Signed-off-by: Like Xu <likexu@tencent.com>
Message-Id: <20220518170118.66263-2-likexu@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>