audit: fix netlink portid naming and types

Normally, netlink ports use the PID of the userspace process as the port ID.
If the PID is already in use by a port, the kernel will allocate another port
ID to avoid conflict.  Re-name all references to netlink ports from pid to
portid to reflect this reality and avoid confusion with actual PIDs.  Ports
use the __u32 type, so re-type all portids accordingly.

(This patch is very similar to ebiederman's 5deadd69)

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
diff --git a/include/linux/audit.h b/include/linux/audit.h
index c9a66c6..9185bfa 100644
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -461,7 +461,7 @@
 				/* Private API (for audit.c only) */
 extern int audit_filter_user(int type);
 extern int audit_filter_type(int type);
-extern int  audit_receive_filter(int type, int pid, int seq,
+extern int  audit_receive_filter(int type, __u32 portid, int seq,
 				void *data, size_t datasz);
 extern int audit_enabled;
 #else /* CONFIG_AUDIT */