Description of problem:
int kvm_arch_irqchip_create(KVMState *s)
{
    if (kvm_kernel_irqchip_split()) {
        perror("-machine kernel_irqchip=split is not supported on ARM.");
        exit(1);
    }

perror will capture the error context and print it with its own message. But there is no error context here, so the error message becomes "-machine kernel_irqchip=split is not supported on ARM.: Success". I think we should cut out ": Success" from the message, even though this is a negative test.

Version-Release number of selected component (if applicable):
qemu-kvm-7.0.0-5.el9.aarch64

How reproducible:
always

Steps to Reproduce:
1. Start qemu process with "-M kernel-irqchip=split"
# /usr/libexec/qemu-kvm -M kernel-irqchip=split

Actual results:
-machine kernel_irqchip=split is not supported on ARM.: Success

Expected results:
Cut ": Success" out from the error message.
-machine kernel_irqchip=split is not supported on ARM.

Additional info:
Only aarch64 does not support kernel-irqchip=split, so this should be an aarch64-specific issue.
https://gitlab.com/qemu-project/qemu/-/blob/master/target/arm/kvm.c#L959-964

Also can reproduce it using upstream qemu.
./build/aarch64-softmmu/qemu-system-aarch64 -version
QEMU emulator version 7.0.50 (v7.0.0-1512-gca127b3fc2)
Copyright (c) 2003-2022 Fabrice Bellard and the QEMU Project developers

./build/aarch64-softmmu/qemu-system-aarch64 -accel kvm -M virt,kernel-irqchip=split
-machine kernel_irqchip=split is not supported on ARM.: Success