slirp: fix unmatched bracket in if 0

Fix unmatched bracket in commented out code

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>

slirp/ip_input.c

@@ -647,8 +647,6 @@ typedef u_int32_t n_time;
 	if (forward) {
 		ip_forward(m, 1);
 		return (1);
-	}
-		}
 	}
 	return (0);
 bad: