drm: Fix mismerge of non-coherent DMA patch

The patch for supporting non coherent PCI DMA in the DRM was mismerged
causing the page protection to be updated for the wrong type of
mapping.

Signed-off-by: Benjamin Herrenschmidt <[e-mail]>
Signed-off-by: Dave Airlie <[e-mail]>

drivers/char/drm/drm_vm.c

···
 		/* Don't let this area swap.  Change when
 		   DRM_KERNEL advisory is supported. */
 		vma->vm_flags |= VM_RESERVED;
-		vma->vm_page_prot = drm_dma_prot(map->type, vma);
 		break;
 	case _DRM_SCATTER_GATHER:
 		vma->vm_ops = &drm_vm_sg_ops;
 		vma->vm_private_data = (void *)map;
 		vma->vm_flags |= VM_RESERVED;
+		vma->vm_page_prot = drm_dma_prot(map->type, vma);
 		break;
 	default:
 		return -EINVAL;	/* This should never happen. */