net/bpfilter: remove superfluous testing message

A testing message was brought by 13d0f7b814 ("net/bpfilter: fix dprintf
usage for /dev/kmsg") but should've been deleted before patch submission.
Although it doesn't cause any harm to the code or functionality itself, it's
totally unpleasant to have it displayed on every loop iteration with no real
use case. Thus remove it unconditionally.

Fixes: 13d0f7b814 ("net/bpfilter: fix dprintf usage for /dev/kmsg")
Signed-off-by: Bruno Meneguele <bmeneg@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/bpfilter/main.c

@@ -35,7 +35,6 @@ static void loop(void)
 		struct mbox_reply reply;
 		int n;
 
-		fprintf(debug_f, "testing the buffer\n");
 		n = read(0, &req, sizeof(req));
 		if (n != sizeof(req)) {
 			fprintf(debug_f, "invalid request %d\n", n);