tc: gred: fix debug print

When build with -DDEBUG, tc build fails with:
q_gred.c: In function ‘init_gred’:
q_gred.c:53:17: error: passing argument 2 of ‘fprintf’ from incompatible pointer type [-Wincompatible-pointer-types]
   53 |                 DPRINTF(stderr, "init_gred: invoked with %s\n", *argv);
      |                 ^~~~~~~
      |                 |
      |                 FILE *

This is due to the DPRINTF macro call. Indeed DPRINTF is defined as a
two-args macro when -DDEBUG is used, while it uses 3 args in this call.

Fix it simply dropping the useless first arg.

Fixes: aba5acdfdb34 ("(Logical change 1.3)")
Signed-off-by: Andrea Claudi <aclaudi@redhat.com>
diff --git a/tc/q_gred.c b/tc/q_gred.c
index 84fc912..9557321 100644
--- a/tc/q_gred.c
+++ b/tc/q_gred.c
@@ -50,7 +50,7 @@
 	opt.def_DP = MAX_DPs;
 
 	while (argc > 0) {
-		DPRINTF(stderr, "init_gred: invoked with %s\n", *argv);
+		DPRINTF("init_gred: invoked with %s\n", *argv);
 		if (strcmp(*argv, "vqs") == 0 ||
 		    strcmp(*argv, "DPs") == 0) {
 			NEXT_ARG();