Handle pcap_findalldevs_ex() on UN*X.

The remote capture stuff, including pcap_findalldevs_ex(), isn't
Windows-specific; libpcap can be built with it on UN*X, although it's
not the *default* configuration.

So, if we're not building for Windows, just #define
ws_pcap_findalldevs_ex to be pcap_findalldevs_ex.

capture/capture-pcap-util.c

@@ -70,6 +70,8 @@
 #include "capture/capture-pcap-util-int.h"
 #ifdef _WIN32
 #include "capture/capture-wpcap.h"
+#else
+#define ws_pcap_findalldevs_ex pcap_findalldevs_ex
 #endif
 
 #include <wsutil/file_util.h>