linked-list: Remove __list_for_each

__list_for_each used to be the non prefetch() aware list walking
primitive.  When we removed the prefetch macros from the list routines,
it became redundant.  Given it does exactly the same thing as
list_for_each now, we might as well remove it and call list_for_each
directly.

All users of __list_for_each have been converted to list_for_each calls
in the current merge window.

Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>