Make the mac_policy_rm lock recursable, which allows reentrance into the mac framework.  It is needed when priv_check_cred(9) is called from the mac callback, e.g. in the mac_portacl(4).
Make the mac_policy_rm lock recursable, which allows reentrance into
the mac framework.  It is needed when priv_check_cred(9) is called from
the mac callback, e.g. in the mac_portacl(4).

Reported by:	az
Reviewed by:	rwatson
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Approved by:	re (gjb)

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