Correctly truncate the rule in case when it has several action opcodes.

It is possible, that opcode at the ACTION_PTR() location is not real
action, but action modificator like "log", "tag" etc. In this case we
need to check for each opcode in the loop to find O_EXTERNAL_ACTION.

Obtained from:	Yandex LLC
Sponsored by:	Yandex LLC

Do not modify cmd pointer if it is already last opcode in the rule.