inet: defines IPPROTO_* needed for module alias generation

Commit cfd280c9 ("net: sync some IP headers with glibc") changed a set of
define's to an enum (with no explanation why) which introduced a bug
in module mip6 where aliases are generated using the IPPROTO_* defines;
mip6 doesn't load if require_module called with the aliases from
xfrm_get_type().

Reverting this change back to define's to fix the aliases.

modinfo mip6 (before this change)
alias:          xfrm-type-10-IPPROTO_DSTOPTS
alias:          xfrm-type-10-IPPROTO_ROUTING

modinfo mip6 (after this change)
alias:          xfrm-type-10-43
alias:          xfrm-type-10-60
Signed-off-by: NJan Moskyto Matejka <mq@suse.cz>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

include/uapi/linux/in6.h

@@ -128,22 +128,13 @@ struct in6_flowlabel_req {
  *	IPV6 extension headers
  */
 #if __UAPI_DEF_IPPROTO_V6
-enum {
-  IPPROTO_HOPOPTS = 0,		/* IPv6 hop-by-hop options      */
-#define IPPROTO_HOPOPTS		IPPROTO_HOPOPTS
-  IPPROTO_ROUTING = 43,		/* IPv6 routing header          */
-#define IPPROTO_ROUTING		IPPROTO_ROUTING
-  IPPROTO_FRAGMENT = 44,	/* IPv6 fragmentation header    */
-#define IPPROTO_FRAGMENT	IPPROTO_FRAGMENT
-  IPPROTO_ICMPV6 = 58,		/* ICMPv6                       */
-#define IPPROTO_ICMPV6		IPPROTO_ICMPV6
-  IPPROTO_NONE = 59,		/* IPv6 no next header          */
-#define IPPROTO_NONE		IPPROTO_NONE
-  IPPROTO_DSTOPTS = 60,		/* IPv6 destination options     */
-#define IPPROTO_DSTOPTS		IPPROTO_DSTOPTS
-  IPPROTO_MH = 135,		/* IPv6 mobility header         */
-#define IPPROTO_MH		IPPROTO_MH
-};
+#define IPPROTO_HOPOPTS		0	/* IPv6 hop-by-hop options	*/
+#define IPPROTO_ROUTING		43	/* IPv6 routing header		*/
+#define IPPROTO_FRAGMENT	44	/* IPv6 fragmentation header	*/
+#define IPPROTO_ICMPV6		58	/* ICMPv6			*/
+#define IPPROTO_NONE		59	/* IPv6 no next header		*/
+#define IPPROTO_DSTOPTS		60	/* IPv6 destination options	*/
+#define IPPROTO_MH		135	/* IPv6 mobility header		*/
 #endif /* __UAPI_DEF_IPPROTO_V6 */
 
 /*