sparc/pci_msi: 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.

@cpumask of irq_set_affinity() is read-only and free of change, drop
unneeded cpumask var.
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Dawei Li <dawei.li@shingroup.cn>
Reviewed-by: Andreas Larsson <andreas@gaisler.com>
Link: https://lore.kernel.org/r/20240424025548.3765250-5-dawei.li@shingroup.cnSigned-off-by: Andreas Larsson <andreas@gaisler.com>

arch/sparc/kernel/pci_msi.c

@@ -287,10 +287,7 @@ static int bringup_one_msi_queue(struct pci_pbm_info *pbm,
 
 	nid = pbm->numa_node;
 	if (nid != -1) {
-		cpumask_t numa_mask;
-
-		cpumask_copy(&numa_mask, cpumask_of_node(nid));
-		irq_set_affinity(irq, &numa_mask);
+		irq_set_affinity(irq, cpumask_of_node(nid));
 	}
 	err = request_irq(irq, sparc64_msiq_interrupt, 0,
 			  "MSIQ",