genirq/msi: Slightly simplify msi_domain_alloc()

The return value of irq_find_mapping() is only tested, not used for
anything else.

Replaced it by irq_resolve_mapping() which is internally used by
irq_find_mapping() and allows a simple boolean decision.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://patch.msgid.link/1ce680114cdb8d40b072c54d7f015696a540e5a6.1760863194.git.christophe.jaillet@wanadoo.fr

Author: tititiou36

kernel/irq/msi.c

@@ -706,7 +706,7 @@ static int msi_domain_alloc(struct irq_domain *domain, unsigned int virq,
 	irq_hw_number_t hwirq = ops->get_hwirq(info, arg);
 	int i, ret;
 
-	if (irq_find_mapping(domain, hwirq) > 0)
+	if (irq_resolve_mapping(domain, hwirq))
 		return -EEXIST;
 
 	if (domain->parent) {