rfkill: Remove obsolete "claim" sysfs interface

This was scheduled to be removed in 2012 by:

commit 69c86373c6ea1149aa559e6088362d58d8ec8835
Author: [e-mail] <[e-mail]>
Date: Wed Feb 24 12:05:16 2010 +0100

Document the rfkill sysfs ABI

This moves sysfs ABI info from Documentation/rfkill.txt to the
ABI subfolder and reformats it.

This also schedules the deprecated sysfs parts to be removed in
2012 (claim file) and 2014 (state file).

Signed-off-by: Florian Mickler <[e-mail]>
Signed-off-by: John W. Linville <[e-mail]>

Signed-off-by: João Paulo Rechi Vita <[e-mail]>
Signed-off-by: Johannes Berg <[e-mail]>

Documentation/ABI/obsolete/sysfs-class-rfkill

···
 		2: RFKILL_STATE_HARD_BLOCKED
 			transmitter is forced off by something outside of
 			the driver's control.
-
-What:		/sys/class/rfkill/rfkill[0-9]+/claim
-Date:		09-Jul-2007
-KernelVersion	v2.6.22
-Contact:	[e-mail]
-Description:	This file is deprecated because there no longer is a way to
-		claim just control over a single rfkill instance.
-		This file is scheduled to be removed in 2012.
-Values: 	0: Kernel handles events

Documentation/ABI/removed/sysfs-class-rfkill

···
+rfkill - radio frequency (RF) connector kill switch support
+
+For details to this subsystem look at Documentation/rfkill.txt.
+
+What:		/sys/class/rfkill/rfkill[0-9]+/claim
+Date:		09-Jul-2007
+KernelVersion	v2.6.22
+Contact:	[e-mail]
+Description:	This file was deprecated because there no longer was a way to
+		claim just control over a single rfkill instance.
+		This file was scheduled to be removed in 2012, and was removed
+		in 2016.
+Values: 	0: Kernel handles events

net/rfkill/core.c

···
  * @blocked: the new state
  *
  * This function sets the state of all switches of given type,
- * unless a specific switch is claimed by userspace (in which case,
- * that switch is left alone) or suspended.
+ * unless a specific switch is suspended.
  *
  * Caller must have acquired rfkill_global_mutex.
  */
···
 }
 static DEVICE_ATTR_RW(state);
 
-static ssize_t claim_show(struct device *dev, struct device_attribute *attr,
-			  char *buf)
-{
-	return sprintf(buf, "%d\n", 0);
-}
-static DEVICE_ATTR_RO(claim);
-
 static struct attribute *rfkill_dev_attrs[] = {
 	&dev_attr_name.attr,
 	&dev_attr_type.attr,
 	&dev_attr_index.attr,
 	&dev_attr_persistent.attr,
 	&dev_attr_state.attr,
-	&dev_attr_claim.attr,
 	&dev_attr_soft.attr,
 	&dev_attr_hard.attr,
 	NULL,