Swap: support freebsd

src/detection/swap/swap_bsd.c

@@ -1,6 +1,8 @@
 #include "swap.h"
+#include "common/sysctl.h"
 
 void ffDetectSwapImpl(FFMemoryStorage* swap)
 {
-    ffStrbufAppendS(&swap->error, "Not implemented");
+    swap->bytesTotal = (uint64_t)ffSysctlGetInt64("vm.swap_total", 0);
+    swap->bytesUsed = (uint64_t)ffSysctlGetInt64("vm.swap_reserved", 0);
 }