mm: move FAULT_FLAG_VMA_LOCK check down in handle_pte_fault()

Call do_pte_missing() under the VMA lock ...  then immediately retry in
do_fault().

Link: https://lkml.kernel.org/r/20230724185410.1124082-7-willy@infradead.org


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