linux-user: Support f_flags in statfs when available.

Signed-off-by: Shea Levy <shea@shealevy.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20180301111500.15717-1-shea@shealevy.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index a8abfd4..e1c3127 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -9545,6 +9545,11 @@
             __put_user(stfs.f_fsid.__val[1], &target_stfs->f_fsid.val[1]);
             __put_user(stfs.f_namelen, &target_stfs->f_namelen);
             __put_user(stfs.f_frsize, &target_stfs->f_frsize);
+#ifdef _STATFS_F_FLAGS
+            __put_user(stfs.f_flags, &target_stfs->f_flags);
+#else
+            __put_user(0, &target_stfs->f_flags);
+#endif
             memset(target_stfs->f_spare, 0, sizeof(target_stfs->f_spare));
             unlock_user_struct(target_stfs, arg2, 1);
         }