Autotest for netpacket/packet.h, as it is not available on all Linux versions.
Depend AF_PACKET on HAVE_NETPACKET_PACKET_H. Fixes #449157
diff --git a/configure.in b/configure.in
index 07e9f09..14d11e8 100644
--- a/configure.in
+++ b/configure.in
@@ -419,7 +419,7 @@
 sys/audioio.h sys/file.h sys/lock.h sys/modem.h db_185.h db.h \
 sys/param.h sys/poll.h sys/select.h sys/socket.h sys/time.h sys/times.h \
 sys/un.h sys/utsname.h sys/wait.h pty.h libutil.h \
-ndbm.h db1/ndbm.h gdbm/ndbm.h sys/resource.h)
+ndbm.h db1/ndbm.h gdbm/ndbm.h sys/resource.h netpacket/packet.h)
 AC_HEADER_DIRENT
 
 # checks for typedefs