Breaking Lustre because of missing kallsyms_lookup_name() isn't really workable.

There needs to be suitable alternatives for:
alloc_workqueue_attrs() / alloc_workqueue_attrs() ... nice but not critical

vfree_atomic() – not needed from v4.10? vfree will call vfree_atomic() when in_interrupt() is true.

Unfortunately we have no way to detect this via configure (aside from guessing based on kernel version).

So just copy the kernel implementation into Luster instead?