RISC-V: KVM: lock the correct mp_state during reset

RISC-V: KVM: lock the correct mp_state during reset

Currently, the kvm_riscv_vcpu_sbi_system_reset() function locks
vcpu->arch.mp_state_lock when updating tmp->arch.mp_state.mp_state
which is incorrect hence fix it.

Fixes: 2121cadec45a ("RISCV: KVM: Introduce mp_state_lock to avoid lock inversion")
Signed-off-by: Radim Krčmář <rkrcmar@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/20250523104725.2894546-4-rkrcmar@ventanamicro.com
Signed-off-by: Anup Patel <anup@brainfault.org>