net/ipv6/icmp.c: Checkpatch cleanups

icmp.c:501: ERROR: "(foo*)" should be "(foo *)"
icmp.c:582: ERROR: "(foo*)" should be "(foo *)"
icmp.c:954: WARNING: EXPORT_SYMBOL(foo); should immediately follow its function/variable

Signed-off-by: Eldad Zack <eldad@fogrefinery.com>
Signed-off-by: David S. Miller <davem@davemloft.net>