Documentation/ABI/rnbd-clt: session name is appended to the device path

When mapping a device,
/sys/devices/virtual/rnbd-client/ctl/devices/<device_id> was created.
But we found out that it had a problem when mapping the same file
on different servers. So we append the session name after the
device_id as below.
/sys/devices/virtual/rnbd-client/ctl/devices/<device_id>@<session_name>

Signed-off-by: Gioh Kim <gi-oh.kim@cloud.ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Documentation/ABI/testing/sysfs-class-rnbd-client

@@ -95,12 +95,12 @@ Description:	Expected format is the following::
 		---------------------------------
 
 		After mapping, the device file can be found by:
-		o  The symlink /sys/class/rnbd-client/ctl/devices/<device_id>
+		o  The symlink /sys/class/rnbd-client/ctl/devices/<device_id>@<session_name>
 		points to /sys/block/<dev-name>. The last part of the symlink destination
 		is the same as the device name.  By extracting the last part of the
 		path the path to the device /dev/<dev-name> can be build.
 
-		* /dev/block/$(cat /sys/class/rnbd-client/ctl/devices/<device_id>/dev)
+		* /dev/block/$(cat /sys/class/rnbd-client/ctl/devices/<device_id>@<session_name>/dev)
 
 		How to find the <device_id> of the device is described on the next
 		section.
@@ -110,7 +110,7 @@ Date:		Feb 2020
 KernelVersion:	5.7
 Contact:	Jack Wang <jinpu.wang@cloud.ionos.com> Danil Kipnis <danil.kipnis@cloud.ionos.com>
 Description:	For each device mapped on the client a new symbolic link is created as
-		/sys/class/rnbd-client/ctl/devices/<device_id>, which points
+		/sys/class/rnbd-client/ctl/devices/<device_id>@<session_name>, which points
 		to the block device created by rnbd (/sys/block/rnbd<N>/).
 		The <device_id> of each device is created as follows: