arm64: consistently log ESR and page table

When we take a fault we can't handle, we try to dump some relevant
information, but we're not consistent about doing so.

In do_mem_abort(), we log the full ESR, but don't dump a page table
walk. In __do_kernel_fault, we dump an attempted decoding of the ESR
(but not the ESR itself) along with a page table walk.

Let's try to make things more consistent by dumping the full ESR in
mem_abort_decode(), and having do_mem_abort dump a page table walk. The
existing dump of the ESR in do_mem_abort() is rendered redundant, and
removed.

Tested-by: Laura Abbott <labbott@redhat.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Julien Thierry <julien.thierry@arm.com>
Cc: Kristina Martsenko <kristina.martsenko@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>