virtio: add unlikely() to WARN_ON_ONCE()

The condition to test is unlikely() to be true. Add the hint.

Signed-off-by: Igor Stoppa <[email protected]>
Cc: "Michael S. Tsirkin" <[email protected]>
Cc: Jason Wang <[email protected]>
Cc: [email protected]
Cc: [email protected]
Signed-off-by: Michael S. Tsirkin <[email protected]>

Author: igor-stoppa

tools/virtio/linux/kernel.h

@@ -127,7 +127,7 @@ static inline void free_page(unsigned long addr)
 #define dev_err(dev, format, ...) fprintf (stderr, format, ## __VA_ARGS__)
 #define dev_warn(dev, format, ...) fprintf (stderr, format, ## __VA_ARGS__)
 
-#define WARN_ON_ONCE(cond) ((cond) ? fprintf (stderr, "WARNING\n") : 0)
+#define WARN_ON_ONCE(cond) (unlikely(cond) ? fprintf (stderr, "WARNING\n") : 0)
 
 #define min(x, y) ({				\
 	typeof(x) _min1 = (x);			\