Documentation: lockstat: Fix typo lokcing -> locking

Cc: Jiri Kosina <trivial@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Documentation/locking/lockstat.txt

@@ -12,7 +12,7 @@ Because things like lock contention can severely impact performance.
 - HOW
 
 Lockdep already has hooks in the lock functions and maps lock instances to
-lock classes. We build on that (see Documentation/lokcing/lockdep-design.txt).
+lock classes. We build on that (see Documentation/locking/lockdep-design.txt).
 The graph below shows the relation between the lock functions and the various
 hooks therein.