ip6mr: Simplify the allocation of slab caches in ip6_mr_init

Use the new KMEM_CACHE() macro instead of direct kmem_cache_create
to simplify the creation of SLAB caches.
And change cache name from 'ip6_mrt_cache' to 'mfc6_cache'.
Signed-off-by: Kunwu Chan <chentao@kylinos.cn>
Reviewed-by: Michal Swiatkowski <michal.swiatkowski@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv6/ip6mr.c

@@ -1373,10 +1373,7 @@ int __init ip6_mr_init(void)
 {
 	int err;
 
-	mrt_cachep = kmem_cache_create("ip6_mrt_cache",
-				       sizeof(struct mfc6_cache),
-				       0, SLAB_HWCACHE_ALIGN,
-				       NULL);
+	mrt_cachep = KMEM_CACHE(mfc6_cache, SLAB_HWCACHE_ALIGN);
 	if (!mrt_cachep)
 		return -ENOMEM;