src: use NFPROTO_ constants

Resync netfilter.h from the latest kernel and make use of the new
NFPROTO_ constants that have been introduced.

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>
diff --git a/libipq/ipq_create_handle.3 b/libipq/ipq_create_handle.3
index c833e88..7840277 100644
--- a/libipq/ipq_create_handle.3
+++ b/libipq/ipq_create_handle.3
@@ -46,7 +46,7 @@
 The
 .I protocol
 parameter is used to specify the protocol of the packets to be queued.
-Valid values are PF_INET for IPv4 and PF_INET6 for IPv6.  Currently, 
+Valid values are NFPROTO_IPV4 for IPv4 and NFPROTO_IPV6 for IPv6. Currently,
 only one protocol may be queued at a time for a handle.
 .PP
 The