RISC-V: KVM: remove a redundant condition in kvm_arch_vcpu_ioctl_run()

The latest ret value is updated by kvm_riscv_vcpu_aia_update(),
the loop will continue if the ret is less than or equal to zero.
So the later condition will never hit. Thus remove it.

Signed-off-by: Chao Du <duchao@eswincomputing.com>
Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Signed-off-by: Anup Patel <anup@brainfault.org>