sparc/leon: Remove on-stack cpumask var

In general it's preferable to avoid placing cpumasks on the stack, as
for large values of NR_CPUS these can consume significant amounts of
stack space and make stack overflows more likely.

Use cpumask_subset() and cpumask_first_and() to avoid the need for a
temporary cpumask on the stack.

Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Dawei Li <dawei.li@shingroup.cn>
Reviewed-by: Andreas Larsson <andreas@gaisler.com>
Tested-by: Andreas Larsson <andreas@gaisler.com>
Link: https://lore.kernel.org/r/20240424025548.3765250-6-dawei.li@shingroup.cn
Signed-off-by: Andreas Larsson <andreas@gaisler.com>

Author: Dawei Li

arch/sparc/kernel/leon_kernel.c

@@ -106,13 +106,12 @@ unsigned long leon_get_irqmask(unsigned int irq)
 #ifdef CONFIG_SMP
 static int irq_choose_cpu(const struct cpumask *affinity)
 {
-	cpumask_t mask;
+	unsigned int cpu = cpumask_first_and(affinity, cpu_online_mask);
 
-	cpumask_and(&mask, cpu_online_mask, affinity);
-	if (cpumask_equal(&mask, cpu_online_mask) || cpumask_empty(&mask))
+	if (cpumask_subset(cpu_online_mask, affinity) || cpu >= nr_cpu_ids)
 		return boot_cpu_id;
 	else
-		return cpumask_first(&mask);
+		return cpu;
 }
 #else
 #define irq_choose_cpu(affinity) boot_cpu_id