osdep: Fix compilation failure on BSD systems

Fix compilation failure on BSD systems (which don't have
O_DIRECT or O_NOATIME:
osdep.c:116: error: ‘O_DIRECT’ undeclared (first use in this function)
osdep.c:116: error: (Each undeclared identifier is reported only once
osdep.c:116: error: for each function it appears in.)
osdep.c:116: error: ‘O_NOATIME’ undeclared (first use in this function)

Reviewed-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

osdep.c

@@ -113,7 +113,13 @@ static int qemu_dup_flags(int fd, int flags)
     }
 
     /* Set/unset flags that we can with fcntl */
-    setfl_flags = O_APPEND | O_ASYNC | O_DIRECT | O_NOATIME | O_NONBLOCK;
+    setfl_flags = O_APPEND | O_ASYNC | O_NONBLOCK;
+#ifdef O_NOATIME
+    setfl_flags |= O_NOATIME;
+#endif
+#ifdef O_DIRECT
+    setfl_flags |= O_DIRECT;
+#endif
     dup_flags &= ~setfl_flags;
     dup_flags |= (flags & setfl_flags);
     if (fcntl(ret, F_SETFL, dup_flags) == -1) {