md/raid1: split out two sub-functions from sync_request_write

sync_request_write is too big and too deep.
So split out two self-contains bits of functionality into separate
function.

Signed-off-by: NeilBrown <neilb@suse.de>
This commit is contained in:
NeilBrown 2011-05-11 14:40:44 +10:00
commit a68e587035