[SCSI] mpt2sas: Fix for Panic when inactive volume is tried deleting

The driver was setting the action to MPI2_CONFIG_ACTION_PAGE_READ_CURRENT,
which only returns active volumes. In order to get info on inactive volumes,
the driver needs to change the action to
MPI2_RAID_PGAD_FORM_GET_NEXT_CONFIGNUM, and traverse each config till the
iocstatus is MPI2_IOCSTATUS_CONFIG_INVALID_PAGE returned.
Added a change in the driver to remove the instance of
sas_device object when the driver returns "1" from the slave_configure callback.
Also fixed code to report the hot spares to the operating system with a /dev/sg
assigned.

Signed-off-by: Nagalakshmi Nandigama <nagalakshmi.nandigama@lsi.com>
Cc: stable@kernel.org
Signed-off-by: James Bottomley <JBottomley@Parallels.com>