s390x/s390-virtio: get rid of DPRINTF

The DPRINTF approach is likely to introduce bitrot, and the preferred
way for debugging is tracing anyway. Fortunately, there are no users
(left), so nuke it.
Signed-off-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: NHalil Pasic <pasic@linux.vnet.ibm.com>
Reviewed-by: NPhilippe Mathieu-Daudé <f4bug@amsat.org>

hw/s390x/s390-virtio.c

@@ -44,16 +44,6 @@
 #include "hw/s390x/ipl.h"
 #include "cpu.h"
 
-//#define DEBUG_S390
-
-#ifdef DEBUG_S390
-#define DPRINTF(fmt, ...) \
-    do { fprintf(stderr, fmt, ## __VA_ARGS__); } while (0)
-#else
-#define DPRINTF(fmt, ...) \
-    do { } while (0)
-#endif
-
 #define MAX_BLK_DEVS                    10
 
 #define S390_TOD_CLOCK_VALUE_MISSING    0x00