genirq/proc: Change the return value for set affinity permission error

Currently, when the affinity of an irq cannot be set due to lack of
permission, the write_irq_affinity() returns the error code -EIO.

Change the return value to -EPERM as that reflects the cause of error
correctly.

Signed-off-by: Jeff Xie <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Link: https://lore.kernel.org/all/[email protected]

Author: Jeff Xie

kernel/irq/proc.c

@@ -140,7 +140,7 @@ static ssize_t write_irq_affinity(int type, struct file *file,
 	int err;
 
 	if (!irq_can_set_affinity_usr(irq) || no_irq_affinity)
-		return -EIO;
+		return -EPERM;
 
 	if (!zalloc_cpumask_var(&new_value, GFP_KERNEL))
 		return -ENOMEM;