raw: Fix valgrind setsockopt warning.

Valgrind is nagging us, saying we pass uninitialized data through a
setsockopt() call.  This patch fixes the issue by clearing the entire
passed structure.

Signed-off-by: Richard Cochran <richardcochran@gmail.com>

raw.c

@@ -103,6 +103,7 @@ static int raw_configure(int fd, int event, int index,
 
 	option = enable ? PACKET_ADD_MEMBERSHIP : PACKET_DROP_MEMBERSHIP;
 
+	memset(&mreq, 0, sizeof(mreq));
 	mreq.mr_ifindex = index;
 	mreq.mr_type = PACKET_MR_MULTICAST;
 	mreq.mr_alen = MAC_LEN;