klist: use same naming scheme as hlist for klist_add_after()

The name was modified from hlist_add_after() to hlist_add_behind() when
adjusting the order of arguments to match the one with
klist_add_after().  This is necessary to break old code when it would
use it the wrong way.

Make klist follow this naming scheme for consistency.

Signed-off-by: Ken Helias <kenhelias@firemail.de>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>