KVM: VMX: Remove redundant check in handle_rmode_exception

Since checking for vcpu->arch.rmode.active is already done whenever we
call handle_rmode_exception(), checking it inside the function is redundant.

Signed-off-by: Mohammed Gamal <m.gamal005@gmail.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>