make -C tools/testing/selftests, compiling dev_in_maps fail.
In file included from dev_in_maps.c:10:
/usr/include/x86_64-linux-gnu/sys/mount.h:35:3: error: expected identifier before numeric constant
35 | MS_RDONLY = 1, /* Mount read-only. */
| ^~~~~~~~~
That sys/mount.h has to be included before linux/mount.h.
Signed-off-by: Meng Li <li.meng@xxxxxxx>