ip6_tunnel:: Correct function name parse_tvl_tnl_enc_lim() in the kerneldoc comments

Fix the following W=1 kernel build warning(s):

 net/ipv6/ip6_tunnel.c:401: warning: expecting prototype for parse_tvl_tnl_enc_lim(). Prototype was for ip6_tnl_parse_tlv_enc_lim() instead
Reported-by: NHulk Robot <hulkci@huawei.com>
Signed-off-by: NXiongfeng Wang <wangxiongfeng2@huawei.com>
Reviewed-by: NDavid Ahern <dsahern@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/ipv6/ip6_tunnel.c

@@ -388,7 +388,7 @@ ip6_tnl_dev_uninit(struct net_device *dev)
 }
 
 /**
- * parse_tvl_tnl_enc_lim - handle encapsulation limit option
+ * ip6_tnl_parse_tlv_enc_lim - handle encapsulation limit option
  *   @skb: received socket buffer
  *   @raw: the ICMPv6 error message data
  *