Add audit_log_type

Add audit_log_type to allow callers to specify type and pid when logging.
Convert audit_log to wrapper around audit_log_type.  Could have
converted all audit_log callers directly, but common case is default
of type AUDIT_KERNEL and pid 0.  Update audit_log_start to take type
and pid values when creating a new audit_buffer.  Move sequences that
did audit_log_start, audit_log_format, audit_set_type, audit_log_end,
to simply call audit_log_type directly.  This obsoletes audit_set_type
and audit_set_pid, so remove them.

Signed-off-by: Chris Wright <chrisw@osdl.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>