arm64/mm: Use generic __pud_free() helper in pud_free() implementation

Commit 0dd4f60a

 ("arm64: mm: Add support for folding PUDs at
runtime") implements specialized PUD alloc/free helpers to allow the
decision whether or not to fold PUDs to be made at runtime when the
number of paging levels is 4 or higher.

Its implementation of pud_free() is based on the generic version that
existed when the patch was first written, but in the meantime, the
freeing of a PUD has become a bit more involved, and so instead of
simply freeing the page, we should invoke the generic __pud_free() that
encapsulates whatever needs doing at this point.

This fixes a reported warning emitted by the page flags
self-diagnostics.

Reported-by: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Tested-by: Ryan Roberts <ryan.roberts@arm.com>
Link: https://lore.kernel.org/r/20240301104046.1234309-5-ardb+git@google.com


Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>