[IPV6] MIP6: Use our standard definitions for paddings.

MIP6_OPT_PAD_X are actually for paddings in destination
option header.  Replace them with our standard IPV6_TLV_PADX.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
diff --git a/include/net/mip6.h b/include/net/mip6.h
index 6327261..a83ad19 100644
--- a/include/net/mip6.h
+++ b/include/net/mip6.h
@@ -28,9 +28,6 @@
 #include <linux/skbuff.h>
 #include <net/sock.h>
 
-#define MIP6_OPT_PAD_1	0
-#define MIP6_OPT_PAD_N	1
-
 /*
  * Mobility Header
  */
diff --git a/net/ipv6/mip6.c b/net/ipv6/mip6.c
index 42403c6..ad1cc5b 100644
--- a/net/ipv6/mip6.c
+++ b/net/ipv6/mip6.c
@@ -44,9 +44,9 @@
 	if (!data)
 		return NULL;
 	if (padlen == 1) {
-		data[0] = MIP6_OPT_PAD_1;
+		data[0] = IPV6_TLV_PAD0;
 	} else if (padlen > 1) {
-		data[0] = MIP6_OPT_PAD_N;
+		data[0] = IPV6_TLV_PADN;
 		data[1] = padlen - 2;
 		if (padlen > 2)
 			memset(data+2, 0, data[1]);