The dma_mask on its own doesn't mean much.  Instead check for the actual
flag.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20190903084615.19161-4-hch@lst.deSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>