block: IBM RamSan 70/80 error message bug fix.

This patch includes a simple change to the rsxx_pci_remove
function that caused error messages because traffic was halted
too early.

Signed-off-by: Philip J Kelleher <pjk1939@linux.vnet.ibm.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>