aic94xx: Skip reading user settings if flash is not found

If no user settings are found it's pointless trying to
read them from flash. So skip that step.
This also fixes a compilation warning about uninitialized variables in
aic94xx.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <JBottomley@Odin.com>