net/xen-netback: off by one in BUG_ON() condition

The > should be >=.  I also added spaces around the '-' operations so
the code is a little more consistent and matches the condition better.

Fixes: f53c3fe8dad7 ('xen-netback: Introduce TX grant mapping')
Acked-by: Konrad Rzeszutek Wilk <Konrad.wilk@oracle>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit 50c2e4dd6749725338621fff456b26d3a592259f)
Signed-off-by: Annie Li <annie.li@oracle.com>

diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c
index ed2d456899144f0c00ab8df708c0dccb790b41d4..f683564ea4a1988eff7c4990d4779b267c858ed4 100644 (file)
--- a/drivers/net/xen-netback/netback.c
+++ b/drivers/net/xen-netback/netback.c
@@ -1566,13 +1566,13 @@ static inline void xenvif_tx_dealloc_action(struct xenvif_queue *queue)
                smp_rmb();
 
                while (dc != dp) {
-                       BUG_ON(gop - queue->tx_unmap_ops > MAX_PENDING_REQS);
+                       BUG_ON(gop - queue->tx_unmap_ops >= MAX_PENDING_REQS);
                        pending_idx =
                                queue->dealloc_ring[pending_index(dc++)];
 
-                       pending_idx_release[gop-queue->tx_unmap_ops] =
+                       pending_idx_release[gop - queue->tx_unmap_ops] =
                                pending_idx;
-                       queue->pages_to_unmap[gop-queue->tx_unmap_ops] =
+                       queue->pages_to_unmap[gop - queue->tx_unmap_ops] =
                                queue->mmap_pages[pending_idx];
                        gnttab_set_unmap_op(gop,
                                            idx_to_kaddr(queue, pending_idx),