[trac5003] Fix up some typos

src/lib/dhcp/pkt_filter_bpf.cc

@@ -555,7 +555,7 @@ PktFilterBPF::send(const Iface& iface, uint16_t sockfd, const Pkt4Ptr& pkt) {
     }
 
     // Loopback interface requires special treatment. It doesn't
-    // use the ethernet header but rather a 4-bytes long pseudo header
+    // use the ethernet header but rather a 4-byte long pseudo header
     // holding an address family type (see bpf.c in OS sources).
     // On OSX, it even lacks pseudo header.
 #if !defined (OS_OSX)

src/lib/dhcp/pkt_filter_inet.cc

@@ -45,7 +45,7 @@ PktFilterInet::openSocket(Iface& iface,
 
     int sock = socket(AF_INET, SOCK_DGRAM, 0);
     if (sock < 0) {
-        isc_throw(SocketConfigError, "Failed to create UDP6 socket.");
+        isc_throw(SocketConfigError, "Failed to create UDP4 socket.");
     }
 
     // Set the close-on-exec flag.

src/lib/dhcp/tests/pkt_filter_bpf_unittest.cc

@@ -181,7 +181,7 @@ TEST_F(PktFilterBPFTest, DISABLED_receive) {
     // Send DHCPv4 message to the local loopback address and server's port.
     sendMessage();
 
-    // Receive the packet using LPF packet filter.
+    // Receive the packet using BPF packet filter.
     Pkt4Ptr rcvd_pkt;
     ASSERT_NO_THROW(rcvd_pkt = pkt_filter.receive(iface, sock_info_));
     // Check that the packet has been correctly received.