vfs: Assert that VOP_READDIR sets *eofflag properly

[markj]

Summary

Suggested by: kib

[kib]

Only cosmetic nits.

sys/kern/vnode_if.src

384

Other _pre and _post macros use lower case

sys/sys/vnode.h

1019

This is pure cosmetic, but we usually add the opening '{' (or do {)in the upper half of the split macro, and closing '}' (} while (0)) in the lower half. See e.g. DROP_GIANT/PICKUP_GIANT.

1024

I would move nresid declaration in the same place as oresid.

1040

[markj]

sys/kern/vnode_if.src

384

I was copying VOP_WRITE in that respect. Should it change too?

[kib]

sys/kern/vnode_if.src

384

I would like this to be done, in separate commit.

[markj]

Handle kib's comments.