lib/sort.c: fix kernel-doc notation warnings

Fix kernel-doc notation in lib/sort.c by using correct function parameter
names.

  lib/sort.c:59: warning: Excess function parameter 'size' description in 'swap_words_32'
  lib/sort.c:83: warning: Excess function parameter 'size' description in 'swap_words_64'
  lib/sort.c:110: warning: Excess function parameter 'size' description in 'swap_bytes'

Link: http://lkml.kernel.org/r/60e25d3d-68d1-bde2-3b39-e4baa0b14907@infradead.org
Fixes: 37d0ec34

 ("lib/sort: make swap functions more generic")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: George Spelvin <lkml@sdf.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>