selftests/mount_settattr: remove duplicate syscall definitions

Which are already defined in wrappers.h.

For now, the syscall defintions of mount_settattr() itself
remain in the test, which is the only test to use them.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Link: https://lore.kernel.org/20250509133240.529330-5-amir73il@gmail.com


Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>