packet: use vzalloc()

alloc_one_pg_vec_page() is supposed to return zeroed memory, so use
vzalloc() instead of vmalloc()
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Cc: Neil Horman <nhorman@tuxdriver.com>
Acked-by: NNeil Horman <nhorman@tuxdriver.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/packet/af_packet.c

@@ -2367,7 +2367,7 @@ static inline char *alloc_one_pg_vec_page(unsigned long order,
 	 * __get_free_pages failed, fall back to vmalloc
 	 */
 	*flags |= PGV_FROM_VMALLOC;
-	buffer = vmalloc((1 << order) * PAGE_SIZE);
+	buffer = vzalloc((1 << order) * PAGE_SIZE);
 
 	if (buffer)
 		return buffer;