scsi_dh: fix reference counting in scsi_dh_activate error path

scsi_dh: fix reference counting in scsi_dh_activate error path

commit 0b8393578c70bc1f09790eeae7d918f38da2e010 upstream.

Commit db422318cbca55168cf965f655471dbf8be82433 ([SCSI] scsi_dh:
propagate SCSI device deletion) introduced a regression where the device
reference is not dropped prior to scsi_dh_activate's early return from
the error path.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>