Fix inclusion of standard headers on non-linux systems

src/main.cpp

@@ -25,8 +25,10 @@ GNU General Public License for more details.
 #include <string>
 #include <sys/stat.h>
 #include <time.h>
-#ifdef OS_LINUX
+#ifdef HAVE_STDLIB_H
  #include <stdlib.h>
+#endif
+#ifdef HAVE_STRING_H
  #include <string.h>
 #endif
 #include "scsiencrypt.h"