Assemble: avoid a consistency check when --force is given.

Assemble: avoid a consistency check when --force is given.

mdadm will normally not include a device into an array if that device
reports that the "best" device has failed, as this normally implies
some sort of inconsistency.
However when --force is given it means that the given drives really
should be assembled if at all possible so in that case the test should
be avoided.

The particular case where this was a problem was a RAID5 were all
devices had the same event count but three of them reported that the
first two had failed.
As they all had the same event count the first was taken as the 'best'
and that caused the later ones to be excluded.  Listing one of the
later ones first allowed the array to be assembled.  So in this case
the test clearly just got in the way and did nothing useful.

Reported-by: "Marek Jaros" <mjaros1@nbox.cz>
Signed-off-by: NeilBrown <neilb@suse.de>