Replace gcc variadic macro extension with C99 version

Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
diff --git a/hw/stellaris_enet.c b/hw/stellaris_enet.c
index c9a0909..d1ec61a 100644
--- a/hw/stellaris_enet.c
+++ b/hw/stellaris_enet.c
@@ -14,14 +14,14 @@
 //#define DEBUG_STELLARIS_ENET 1
 
 #ifdef DEBUG_STELLARIS_ENET
-#define DPRINTF(fmt, args...) \
-do { printf("stellaris_enet: " fmt , ##args); } while (0)
-#define BADF(fmt, args...) \
-do { fprintf(stderr, "stellaris_enet: error: " fmt , ##args); exit(1);} while (0)
+#define DPRINTF(fmt, ...) \
+do { printf("stellaris_enet: " fmt , ## __VA_ARGS__); } while (0)
+#define BADF(fmt, ...) \
+do { fprintf(stderr, "stellaris_enet: error: " fmt , ## __VA_ARGS__); exit(1);} while (0)
 #else
-#define DPRINTF(fmt, args...) do {} while(0)
-#define BADF(fmt, args...) \
-do { fprintf(stderr, "stellaris_enet: error: " fmt , ##args);} while (0)
+#define DPRINTF(fmt, ...) do {} while(0)
+#define BADF(fmt, ...) \
+do { fprintf(stderr, "stellaris_enet: error: " fmt , ## __VA_ARGS__);} while (0)
 #endif
 
 #define SE_INT_RX       0x01