Replace non existing DLT constants with available ones.  Adapt
description to OpenBSD names.

Index: t/14-datalink.t
--- t/14-datalink.t.orig
+++ t/14-datalink.t
@@ -12,7 +12,7 @@ plan skip_all => "extended datalink related functions 
 
 %name2val = (
     undef            => -1, 
-    LTalk            => DLT_LTALK, 
+    ProNET           => DLT_PRONET, 
     raw              => DLT_RAW, 
     PPP_serial       => DLT_PPP_SERIAL, 
     SLIP             => DLT_SLIP, 
@@ -20,20 +20,19 @@ plan skip_all => "extended datalink related functions 
 );
 %val2name = (
     0                => 'NULL', 
-    DLT_LTALK()      => 'LTALK', 
+    DLT_PRONET()      => 'PRONET', 
     DLT_RAW()        => 'RAW', 
     DLT_PPP_SERIAL() => 'PPP_SERIAL', 
     DLT_SLIP()       => 'SLIP', 
     DLT_IEEE802_11() => 'IEEE802_11', 
 );
 %val2descr = (
-    0                => 'BSD loopback', 
-    DLT_NULL()       => 'BSD loopback', 
-    DLT_LTALK()      => 'Localtalk', 
-    DLT_RAW()        => 'Raw IP', 
+    DLT_NULL()       => 'no link-layer encapsulation', 
+    DLT_PRONET()      => 'Proteon ProNET Token Ring', 
+    DLT_RAW()        => 'raw IP', 
     DLT_PPP_SERIAL() => 'PPP over serial', 
-    DLT_SLIP()       => 'SLIP', 
-    DLT_IEEE802_11() => '802.11', 
+    DLT_SLIP()       => 'Serial Line IP', 
+    DLT_IEEE802_11() => 'IEEE 802.11 wireless', 
 );
 
 plan tests => keys(%name2val) * 2 + keys(%val2name) * 2 + keys(%val2descr) * 2 + 23;
@@ -104,7 +103,7 @@ SKIP: {
     like( $datalink , '/^\d+$/', " - datalink is an integer" );
 
     # Testing set_datalink()
-    eval { $r = Net::Pcap::set_datalink($pcap, DLT_LTALK) };  # Apple LocalTalk
+    eval { $r = Net::Pcap::set_datalink($pcap, DLT_PRONET) };  # ProNET
     is( $@, '', "set_datalink() on a live connection" );
     is( $r , -1, " - returned -1 (expected failure)" );
 
@@ -123,7 +122,7 @@ like( $datalink , '/^\d+$/', " - datalink is an intege
 is( $datalink , DLT_EN10MB, " - datalink is DLT_EN10MB (Ethernet)" );
 
 # Testing set_datalink()
-eval { $r = Net::Pcap::set_datalink($pcap, DLT_LTALK) };  # Apple LocalTalk
+eval { $r = Net::Pcap::set_datalink($pcap, DLT_PRONET) };  # ProNET
 is( $@, '', "set_datalink() on a save file" );
 is( $r , -1, " - returned -1 (expected failure)" );
 
@@ -131,24 +130,24 @@ Net::Pcap::close($pcap);
 
 
 # Open a dead pcap descriptor
-$pcap = Net::Pcap::open_dead(DLT_IP_OVER_FC, 1024);
+$pcap = Net::Pcap::open_dead(DLT_IEEE802_11_RADIO, 1024);
 isa_ok( $pcap, 'pcap_tPtr', "\$pcap" );
 
 # Testing datalink()
 $datalink = '';
 eval { $datalink = Net::Pcap::datalink($pcap) };
 is( $@, '', "datalink() on a dead descriptor" );
-is( $datalink , DLT_IP_OVER_FC, " - datalink is an integer" );
+is( $datalink , DLT_IEEE802_11_RADIO, " - datalink is an integer" );
 
 # Testing set_datalink()
-# the migration of the century: from IP-over-Fibre Channel to Apple LocalTalk!
-eval { $r = Net::Pcap::set_datalink($pcap, DLT_LTALK) };
+# the migration of the century: from 802.11 WLAN header to ProNET!
+eval { $r = Net::Pcap::set_datalink($pcap, DLT_PRONET) };
 is( $@, '', "set_datalink() on a dead descriptor" );
 is( $r , -1, " - returned -1 (expected failure)" );
 # The following tests don't work, but maybe they're just incorrect. 
 #isnt( $r , -1, " - should not returned -1" );
 #$datalink = Net::Pcap::datalink($pcap);
-#is( $datalink, DLT_LTALK, " - new link type was correctly stored" );
+#is( $datalink, DLT_PRONET, " - new link type was correctly stored" );
 
 
 # Testing datalink_name_to_val()