Upgrade libpcap to 1.8.1 (Nmap-specific patches not yet applied)

libpcap/etherent.c

@@ -23,9 +23,9 @@
 #include "config.h"
 #endif
 
-#ifdef WIN32
+#ifdef _WIN32
 #include <pcap-stdinc.h>
-#else /* WIN32 */
+#else /* _WIN32 */
 #if HAVE_INTTYPES_H
 #include <inttypes.h>
 #elif HAVE_STDINT_H
@@ -35,7 +35,7 @@
 #include <sys/bitypes.h>
 #endif
 #include <sys/types.h>
-#endif /* WIN32 */
+#endif /* _WIN32 */
 
 #include <ctype.h>
 #include <memory.h>