LU-6142 lov: make various lov_object.c function static.

LU-6142 lov: make various lov_object.c function static.

These function in lov_object.c and lovsub_object.c are only
used in the file in which they are defined.
So mark them as static.

Test-Parameters: trivial
Signed-off-by: Mr NeilBrown <neilb@suse.de>
Change-Id: I958f4e850d13d2ced32772e0e66627eb40a1bf36
Reviewed-on: https://review.whamcloud.com/39385
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: James Simmons <jsimmons@infradead.org>
Reviewed-by: Lai Siyao <lai.siyao@whamcloud.com>
Reviewed-by: Arshad Hussain <arshad.super@gmail.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>