arm64/mm: Refactor {pgd, pud, pmd, pte}_ERROR()

arm64/mm: Refactor {pgd, pud, pmd, pte}_ERROR()

The function __{pgd, pud, pmd, pte}_error() are introduced so that
they can be called by {pgd, pud, pmd, pte}_ERROR(). However, some
of the functions could never be called when the corresponding page
table level isn't enabled. For example, __{pud, pmd}_error() are
unused when PUD and PMD are folded to PGD.

This removes __{pgd, pud, pmd, pte}_error() and call pr_err() from
{pgd, pud, pmd, pte}_ERROR() directly, similar to what x86/powerpc
are doing. With this, the code looks a bit simplified either.

Signed-off-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Link: https://lore.kernel.org/r/20200913234730.23145-1-gshan@redhat.com
Signed-off-by: Will Deacon <will@kernel.org>