mm: handle swap and NUMA PTE faults under the VMA lock

mm: handle swap and NUMA PTE faults under the VMA lock

Move the FAULT_FLAG_VMA_LOCK check down in handle_pte_fault().  This is
probably not a huge win in its own right, but is a nicely separable bit
from the next patch.

Link: https://lkml.kernel.org/r/20230724185410.1124082-10-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Arjun Roy <arjunroy@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Punit Agrawal <punit.agrawal@bytedance.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>