If XL cannot properly attach it tries to detach to clean up. Unfortunately,

If XL cannot properly attach it tries to detach to clean up.  Unfortunately,
the detach code expects it to have gotten most of the way through the attach
and if it hasn't the system will crash.  This commit adds a flag that tells
the detach code whether the attach got far enough along for the detach to
be able to reset the card (and do certain other things).