scsi: configure runtime pm before calling device_add in scsi_add_host_with_dma

Runtime PM should be configured already once we call device_add. See
also the description in this mail thread
https://lists.linuxfoundation.org/pipermail/linux-pm/2009-November/023198.html


or the order of calls e.g. in usb_new_device.

The changed order also helps to avoid scenarios where runtime pm for
&shost->shost_gendev is activated whilst the parent is suspended,
resulting in error message "runtime PM trying to activate child device
hostx but parent yyy is not active".

In addition properly reverse the runtime pm calls in the error path.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>