In shared SAS configurations we might get a busy status
during driver initiated commands (e.g. during rescan for
devices).  We should retry the command in such cases rather
than giving up.
Signed-off-by: Matt Bondurant <Matthew.dav.bondurant@hp.com>
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>