locking/barriers, arch: Remove ambiguous statement in the smp_store_mb() documentation

It serves no purpose but to confuse readers, and is most
likely a left over from constant memory-barriers.txt
updates. I.e.:

  http://lists.openwall.net/linux-kernel/2006/07/15/27Signed-off-by: Davidlohr Bueso <dave@stgolabs.net>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <linux-arch@vger.kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1445975631-17047-5-git-send-email-dave@stgolabs.netSigned-off-by: Ingo Molnar <mingo@kernel.org>

Documentation/memory-barriers.txt

@@ -1673,8 +1673,8 @@ There are some more advanced barrier functions:
  (*) smp_store_mb(var, value)
 
      This assigns the value to the variable and then inserts a full memory
-     barrier after it, depending on the function.  It isn't guaranteed to
-     insert anything more than a compiler barrier in a UP compilation.
+     barrier after it.  It isn't guaranteed to insert anything more than a
+     compiler barrier in a UP compilation.
 
 
  (*) smp_mb__before_atomic();