LU-8054 lfsck: enhance lfsck notify API

LU-8054 lfsck: enhance lfsck notify API

Originally, the lfsck_in_notify() contains too much functionalities,
including both the remote LFSCK control and local LFSCK notification.
These LFSCK requirements/callers share the structure "lfsck_request"
to transfer kinds of data, as to it is very difficult to enhance the
"lfsck_request" for more local LFSCK requirements. Because enlarging
or adjusting the "lfsck_request" fields will affect the LFSCK RPC on
wire protocol and cause interoperability issues.

The patch splits the local LFSCK notifications from lfsck_in_notify(),
and introduce new LFSCK API lfsck_in_notify_local() for them. Then
even if we have more local LFSCK requirements in the future, we can
enhance such API freely without affecting LFSCK RPC protocol.

Reviewed-on: https://review.whamcloud.com/24881

Signed-off-by: Fan Yong <fan.yong@intel.com>
Change-Id: I8f285c6680de66a73050e167dc3874a4f6bf4ad0
Reviewed-by: Niu Yawei <yawei.niu@intel.com>
Reviewed-by: Bobi Jam <bobijam@hotmail.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>