virtio: fix BAD_RING, START_US and END_USE macros

Impact: cleanup

fix BAD_RING, START_US and END_USE macros

When these macros aren't called with a variable named vq as first
argument, this would result in a build failure.
Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

drivers/virtio/virtio_ring.c

@@ -23,15 +23,15 @@
 
 #ifdef DEBUG
 /* For development, we want to crash whenever the ring is screwed. */
-#define BAD_RING(vq, fmt...)			\
-	do { dev_err(&vq->vq.vdev->dev, fmt); BUG(); } while(0)
-#define START_USE(vq) \
-	do { if ((vq)->in_use) panic("in_use = %i\n", (vq)->in_use); (vq)->in_use = __LINE__; mb(); } while(0)
-#define END_USE(vq) \
-	do { BUG_ON(!(vq)->in_use); (vq)->in_use = 0; mb(); } while(0)
+#define BAD_RING(_vq, fmt...)			\
+	do { dev_err(&_vq->vq.vdev->dev, fmt); BUG(); } while(0)
+#define START_USE(_vq) \
+	do { if ((_vq)->in_use) panic("in_use = %i\n", (_vq)->in_use); (_vq)->in_use = __LINE__; mb(); } while(0)
+#define END_USE(_vq) \
+	do { BUG_ON(!(_vq)->in_use); (_vq)->in_use = 0; mb(); } while(0)
 #else
-#define BAD_RING(vq, fmt...)			\
-	do { dev_err(&vq->vq.vdev->dev, fmt); (vq)->broken = true; } while(0)
+#define BAD_RING(_vq, fmt...)			\
+	do { dev_err(&_vq->vq.vdev->dev, fmt); (_vq)->broken = true; } while(0)
 #define START_USE(vq)
 #define END_USE(vq)
 #endif