netfilter: ipset: Improve preprocessor macros checks

Check if mandatory MTYPE, HTYPE and HOST_MASK macros
defined.
Signed-off-by: Sergey Popovich <popovich_sergei@mail.ua>
Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

net/netfilter/ipset/ip_set_hash_gen.h

@@ -253,6 +253,14 @@ hbucket_elem_add(struct hbucket *n, u8 ahash_max, size_t dsize)
 #define mtype_variant		IPSET_TOKEN(MTYPE, _variant)
 #define mtype_data_match	IPSET_TOKEN(MTYPE, _data_match)
 
+#ifndef MTYPE
+#error "MTYPE is not defined!"
+#endif
+
+#ifndef HOST_MASK
+#error "HOST_MASK is not defined!"
+#endif
+
 #ifndef HKEY_DATALEN
 #define HKEY_DATALEN		sizeof(struct mtype_elem)
 #endif
@@ -262,6 +270,9 @@ hbucket_elem_add(struct hbucket *n, u8 ahash_max, size_t dsize)
 	& jhash_mask(htable_bits))
 
 #ifndef htype
+#ifndef HTYPE
+#error "HTYPE is not defined!"
+#endif /* HTYPE */
 #define htype			HTYPE
 
 /* The generic hash structure */
@@ -288,7 +299,7 @@ struct htype {
 	struct net_prefixes nets[0]; /* book-keeping of prefixes */
 #endif
 };
-#endif
+#endif /* htype */
 
 #ifdef IP_SET_HASH_WITH_NETS
 /* Network cidr size book keeping when the hash stores different