target/loongarch: Clean up virt_cpu_irq_init() error handling

target/loongarch: Clean up virt_cpu_irq_init() error handling

The Error ** argument must be NULL, &error_abort, &error_fatal, or a
pointer to a variable containing NULL. Passing an argument of the
latter kind twice without clearing it in between is wrong: if the
first call sets an error, it no longer points to NULL for the second
call.

virt_cpu_irq_init() is wrong that way: it passes &err to
hotplug_handler_plug() twice.  If both calls failed, this could trip
error_setv()'s assertion.  Moreover, if just one fails, the Error
object leaks. Fortunately, these calls can't actually fail.

Messed up in commit 50ebc3fc47f7 (hw/intc/loongarch_ipi: Notify ipi
object when cpu is plugged) and commit 087a23a87c57
(hw/intc/loongarch_extioi: Use cpu plug notification).

Clean this up by passing &error_abort instead.

Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Acked-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20250320032158.1762751-7-maobibo@loongson.cn>
Signed-off-by: Markus Armbruster <armbru@redhat.com>