MFC r300870,r300884:

r300870:

Unbreak the zfs(4) build

vm/vm_pageout.h grew a dependency on the bool typedef in r300865

arc.c didn't include sys/types.h, which included the definition for the typedef

Other items (ofed, drm2) might need to be chased for this commit.

Pointyhat to: alc

r300884:

Fix up r300870

The sys/types.h fix I proposed was only tested with zfs(4), not with
libzpool, which is where the build failure actually existed

Remove vm/vm_pageout.h from arc.c and zfs_vnops.c because they're both
unneeded

In collaboration with: kib