Memory (OpenBSD): update formula to be consistant with other systems

Author: CarterLi

src/detection/memory/memory_obsd.c

@@ -2,10 +2,7 @@
 #include "common/sysctl.h"
 
 #include <sys/param.h>
-
-#if __NetBSD__
-    #include <uvm/uvm_extern.h>
-#endif
+#include <uvm/uvm_extern.h>
 
 const char* ffDetectMemory(FFMemoryResult* ram)
 {
@@ -15,7 +12,7 @@ const char* ffDetectMemory(FFMemoryResult* ram)
         return "sysctl(CTL_VM, VM_UVMEXP) failed";
 
     ram->bytesTotal = (uint64_t) buf.npages * instance.state.platform.sysinfo.pageSize;
-    ram->bytesUsed = ram->bytesTotal - (uint64_t) buf.free * instance.state.platform.sysinfo.pageSize;
+    ram->bytesUsed = ((uint64_t) buf.active + (uint64_t) buf.inactive + (uint64_t) buf.wired) * instance.state.platform.sysinfo.pageSize;
 
     return NULL;
 }