LU-13602 flr: skip unknown FLR component types

LU-13602 flr: skip unknown FLR component types

Currently, in lov_init_composite() it will quit with error when
reading an unknown LOV pattern.
Since FLR will be used for upcoming new features, like PCC-RO,
an old client should be able to read the old format of the
component types, ignore and skip the new types of FLR component.

Signed-off-by: Qian Yingjin <qian@ddn.com>
Change-Id: Ica3fe98203d44b52cf25b085c34c83b1a4702464
Reviewed-on: https://review.whamcloud.com/39513
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>