SCSI: esp: tidy up target reference counting

SCSI: esp: tidy up target reference counting

commit ec5e69f6d3f4350681d6f7eaae515cf014be9276 upstream

The esp driver currently does hand rolled reference counting of its
target.  It's much easier to do what it needs to do if it's plugged into
the mid-layer callbacks (target_alloc and target_destroy) which were
designed for this case, so do it this way and get rid of the internal
target reference count.

Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>