genirq/irq_sim: Shrink code by using <linux/cleanup.h> helpers

Use the new __free() mechanism to remove all gotos and simplify the error
paths.

Signed-off-by: Bartosz Golaszewski <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Nathan Chancellor <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

Author: Bartosz Golaszewski

kernel/irq/irq_sim.c

@@ -4,6 +4,7 @@
  * Copyright (C) 2020 Bartosz Golaszewski <[email protected]>
  */
 
+#include <linux/cleanup.h>
 #include <linux/interrupt.h>
 #include <linux/irq.h>
 #include <linux/irq_sim.h>
@@ -163,33 +164,27 @@ static const struct irq_domain_ops irq_sim_domain_ops = {
 struct irq_domain *irq_domain_create_sim(struct fwnode_handle *fwnode,
 					 unsigned int num_irqs)
 {
-	struct irq_sim_work_ctx *work_ctx;
+	struct irq_sim_work_ctx *work_ctx __free(kfree) =
+				kmalloc(sizeof(*work_ctx), GFP_KERNEL);
 
-	work_ctx = kmalloc(sizeof(*work_ctx), GFP_KERNEL);
 	if (!work_ctx)
-		goto err_out;
+		return ERR_PTR(-ENOMEM);
 
-	work_ctx->pending = bitmap_zalloc(num_irqs, GFP_KERNEL);
-	if (!work_ctx->pending)
-		goto err_free_work_ctx;
+	unsigned long *pending __free(bitmap) = bitmap_zalloc(num_irqs, GFP_KERNEL);
+	if (!pending)
+		return ERR_PTR(-ENOMEM);
 
 	work_ctx->domain = irq_domain_create_linear(fwnode, num_irqs,
 						    &irq_sim_domain_ops,
 						    work_ctx);
 	if (!work_ctx->domain)
-		goto err_free_bitmap;
+		return ERR_PTR(-ENOMEM);
 
 	work_ctx->irq_count = num_irqs;
 	work_ctx->work = IRQ_WORK_INIT_HARD(irq_sim_handle_irq);
+	work_ctx->pending = no_free_ptr(pending);
 
-	return work_ctx->domain;
-
-err_free_bitmap:
-	bitmap_free(work_ctx->pending);
-err_free_work_ctx:
-	kfree(work_ctx);
-err_out:
-	return ERR_PTR(-ENOMEM);
+	return no_free_ptr(work_ctx)->domain;
 }
 EXPORT_SYMBOL_GPL(irq_domain_create_sim);