scsi: hpsa: check for tag collision

Correct rare multipath issue where a device is deleted with an
outstanding cmd which results in a tag collision.

The cmd eventually completes. If a collision is detected wait until
the command slot is cleared.

Reviewed-by: Justin Lindley <justin.lindley@microsemi.com>
Reviewed-by: David Carroll <david.carroll@microsemi.com>
Reviewed-by: Scott Teel <scott.teel@microsemi.com>
Signed-off-by: Don Brace <don.brace@microsemi.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>