doc: Fix typo in doucmentations

Correct typo (double words) in documentations.

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

Documentation/sysfs-rules.txt

@@ -47,7 +47,7 @@ versions of the sysfs interface.
         at device creation and removal
       - the unique key to the device at that point in time
       - the kernel's path to the device directory without the leading
-        /sys, and always starting with with a slash
+        /sys, and always starting with a slash
       - all elements of a devpath must be real directories. Symlinks
         pointing to /sys/devices must always be resolved to their real
         target and the target path must be used to access the device.