netfilter: xt_ipcomp: add "ip[6]t_ipcomp" module alias name

Otherwise, user cannot add related rules if xt_ipcomp.ko is not loaded:
  # iptables -A OUTPUT -p 108 -m ipcomp --ipcompspi 1
  iptables: No chain/target/match by that name.
Signed-off-by: Liping Zhang <liping.zhang@spreadtrum.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

net/netfilter/xt_ipcomp.c

@@ -26,6 +26,8 @@
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Fan Du <fan.du@windriver.com>");
 MODULE_DESCRIPTION("Xtables: IPv4/6 IPsec-IPComp SPI match");
+MODULE_ALIAS("ipt_ipcomp");
+MODULE_ALIAS("ip6t_ipcomp");
 
 /* Returns 1 if the spi is matched by the range, 0 otherwise */
 static inline bool