From: Petr Vandrovec <vandrove@vc.cvut.cz>

bk-dma-decleare-coherent-memory patch adds a requirement for
dma_free_coherent that dev cannot be NULL...  But it can (nsc-ircc has no
suitable dev) and as dma_alloc_coherent allows NULL dev, dma_free_coherent
should allow it too IMHO.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>