Remove BYTE directives from kernel linker script to fix triple fault on boot

The superblock is read when the first process returns to
userspace (via the call to `iinit` from the first invocation of
`forkret`, when `first` is still set to 1) and cached in a
global; it is treated as immutable from that point on.  There is
no reason to re-read it in bfree.

Removing this call seems to have simply been missed in 8320d61b


when this general area was last touched.  Remove it now to avoid
potential confusion.

Signed-off-by: Dan Cross <cross@gajendra.net>

The `off` argument to `dirlookup` is optional.  It
was not being used in the `dirlookup` call in `create`,
so pass NULL instead and delete the unused local.

Signed-off-by: Dan Cross <cross@gajendra.net>

Use generic 6.828 url (without year)

Adjust typesetting of code

be more specific (thanks Mark Morrissey)

from picirq.c and remove timer.c completely.  Update runoff.list.