pci_dma_mapping_error can't be used for pci_alloc_consistent
(pci_dma_mapping_error is for dma_map_single and dma_map_page).
pci_alloc_consistent returns NULL if the allocation fails.
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: NIgor M. Liplianin <liplianin@me.by>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>