mfd: sm501: Fix leaks in probe()

This code should clean up if sm501_init_dev() fails.

Fixes: b6d6454fdb66 ("[PATCH] mfd: SM501 core driver")
Signed-off-by: Dan Carpenter <[e-mail]>
Signed-off-by: Lee Jones <[e-mail]>

drivers/mfd/sm501.c

···
 		goto err_claim;
 	}
 
-	return sm501_init_dev(sm);
+	ret = sm501_init_dev(sm);
+	if (ret)
+		goto err_unmap;
 
+	return 0;
+
+ err_unmap:
+	iounmap(sm->regs);
  err_claim:
 	release_mem_region(sm->io_res->start, 0x100);
  err_res: