Documentation/locking/lockdep: Update info about states

Commit:

  d92a8cfc ("locking/lockdep: Rework FS_RECLAIM annotation")

removed the 'reclaim_fs' lockdep STATE.

Reflect the change in the documentation.

While we are at it, also clarify the formula to calculate the number of state bits.
Signed-off-by: Juri Lelli <juri.lelli@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-doc@vger.kernel.org
Link: http://lkml.kernel.org/r/20180213185519.18186-2-juri.lelli@redhat.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

Documentation/locking/lockdep-design.txt

@@ -27,7 +27,8 @@ lock-class.
 State
 -----
 
-The validator tracks lock-class usage history into 4n + 1 separate state bits:
+The validator tracks lock-class usage history into 4 * nSTATEs + 1 separate
+state bits:
 
 - 'ever held in STATE context'
 - 'ever held as readlock in STATE context'
@@ -37,7 +38,6 @@ The validator tracks lock-class usage history into 4n + 1 separate state bits:
 Where STATE can be either one of (kernel/locking/lockdep_states.h)
  - hardirq
  - softirq
- - reclaim_fs
 
 - 'ever used'                                       [ == !unused        ]