documentation: drivers/core/of: fix name of of_node symlink

commit 5590f319 ("drivers/core/of: Add symlink to device-tree from
devices with an OF node") added a symlink called "of_node" to sysfs
however the documentation describes it as "of_path".

Fix the documentation to match what the code actually does.
Signed-off-by: Martin Fuzzey <mfuzzey@parkeon.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/ABI/stable/sysfs-devices

 # Note: This documents additional properties of any device beyond what
 # is documented in Documentation/sysfs-rules.txt
 
-What:		/sys/devices/*/of_path
+What:		/sys/devices/*/of_node
 Date:		February 2015
 Contact:	Device Tree mailing list <devicetree@vger.kernel.org>
 Description: