xfrm: checkpatch errors with foo * bar

This patch clean up some checkpatch errors like this:
ERROR: "foo * bar" should be "foo *bar"
ERROR: "(foo*)" should be "(foo *)"

Signed-off-by: Weilong Chen <chenweilong@huawei.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>