vfio: remove DPRINTF() definition from vfio-common.h

This macro isn't used by any VFIO code. And its name is
too generic. The vfio-common.h (in include/hw/vfio) can
be included by other modules in QEMU. It can introduce
conflicts.

Signed-off-by: Tiwei Bie <tiwei.bie@intel.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

include/hw/vfio/vfio-common.h

@@ -33,15 +33,6 @@
 #define ERR_PREFIX "vfio error: %s: "
 #define WARN_PREFIX "vfio warning: %s: "
 
-/*#define DEBUG_VFIO*/
-#ifdef DEBUG_VFIO
-#define DPRINTF(fmt, ...) \
-    do { fprintf(stderr, "vfio: " fmt, ## __VA_ARGS__); } while (0)
-#else
-#define DPRINTF(fmt, ...) \
-    do { } while (0)
-#endif
-
 enum {
     VFIO_DEVICE_TYPE_PCI = 0,
     VFIO_DEVICE_TYPE_PLATFORM = 1,