LU-14502 lov: fault page update cp_lov_index

LU-14502 lov: fault page update cp_lov_index

In fault IO, vvp_io_fault_start() could find an existing cl_page
associated with the vmpage covering the fault index, and the page
may still refer to another mirror of an old IO.

This patch update the fault page's cp_lov_index in lov_io_fault_start

Signed-off-by: Bobi Jam <bobijam@whamcloud.com>
Change-Id: I50639700159a76061437fd2f1a09dadf25cfd33f
Reviewed-on: https://review.whamcloud.com/41954
Reviewed-by: Wang Shilong <wshilong@whamcloud.com>
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>