KVM: nVMX: Fix the update value of nested load IA32_PERF_GLOBAL_CTRL control

A minor fix for the update of VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL field
in exit_ctls_high.

Fixes: 03a8871a

 ("KVM: nVMX: Expose load IA32_PERF_GLOBAL_CTRL
VM-{Entry,Exit} control")
Signed-off-by: Chenyi Qiang <chenyi.qiang@intel.com>
Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>
Message-Id: <20200828085622.8365-5-chenyi.qiang@intel.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>