virtio: rename virtqueue_add_buf_gfp to virtqueue_add_buf

Remove wrapper functions. This makes the allocation type explicit in
all callers; I used GPF_KERNEL where it seemed obvious, left it at
GFP_ATOMIC otherwise.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Reviewed-by: Christoph Hellwig <hch@lst.de>
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index 4d0b70a..a345e40 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -172,7 +172,7 @@
 		}
 	}
 
-	if (virtqueue_add_buf(vblk->vq, vblk->sg, out, in, vbr) < 0) {
+	if (virtqueue_add_buf(vblk->vq, vblk->sg, out, in, vbr, GFP_ATOMIC)<0) {
 		mempool_free(vbr, vblk->pool);
 		return false;
 	}