RISC-V: KVM: fix PMU snapshot_set_shmem on 32-bit hosts

RISC-V: KVM: fix PMU snapshot_set_shmem on 32-bit hosts

When saddr_high != 0 on RV32, the goto out was unconditional, causing
valid 64-bit addresses to be rejected. Only goto out when the address
is invalid (64-bit host with saddr_high != 0).

Fixes: c2f41ddbcdd7 ("RISC-V: KVM: Implement SBI PMU Snapshot feature")
Signed-off-by: Osama Abdelkader <osama.abdelkader@gmail.com>
Reviewed-by: Andrew Jones <andrew.jones@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20260311231833.13189-1-osama.abdelkader@gmail.com
Signed-off-by: Anup Patel <anup@brainfault.org>