lib/test_free_pages.c: pass a pointer to virt_to_page()

lib/test_free_pages.c: pass a pointer to virt_to_page()

In a recent change to the Arm architecture with the end goal of removing
highmem we need to convert virt_to_phys() and virt_to_pfn() to static
inline functions.

This will make them strongly typed.

However since virt_to_* is always implemented as macros they have become
polymorphic and accept both (void *) and e.g.  unsigned long as arguments.

Other functions such as virt_to_page() simply wrap virt_to_pfn() and get
affected indirectly.

To be able to proceed, patch mm to use (void *) as argument to affected
functions in all instances.

This patch (of 5):

A pointer into virtual memory is represented by a (void *) not an u32, so
the compiler warns:

lib/test_free_pages.c:20:50: warning: passing argument 1
  of 'virt_to_pfn' makes pointer from integer without a
  cast [-Wint-conversion]

Fix this with an explicit cast.

Link: https://lkml.kernel.org/r/20220630084124.691207-1-linus.walleij@linaro.org
Link: https://lkml.kernel.org/r/20220630084124.691207-2-linus.walleij@linaro.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Marco Elver <elver@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>