audit: do not cast audit_rule_data pointers pointlesly

For some sort of legacy support audit_rule is a subset of (and first
entry in) audit_rule_data.  We don't actually need or use audit_rule.
We just do a cast from one to the other for no gain what so ever.  Stop
the crazy casting.

Signed-off-by: Eric Paris <eparis@redhat.com>

diff --cc kernel/auditfilter.c
Simple merge