staging/lustre/llite: move vvp_io functions to vvp_io.c

staging/lustre/llite: move vvp_io functions to vvp_io.c

Move all vvp_io related functions from lustre/llite/lcommon_cl.c to
the sole file where they are used lustre/llite/vvp_io.c.

Signed-off-by: John L. Hammond <john.hammond@intel.com>
Reviewed-on: http://review.whamcloud.com/13376
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-5971
Reviewed-by: Jinshan Xiong <jinshan.xiong@intel.com>
Reviewed-by: Bobi Jam <bobijam@hotmail.com>
Signed-off-by: Oleg Drokin <green@linuxhacker.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>