mm/nommu: remove unnecessary VMA locking

mm/nommu: remove unnecessary VMA locking

Since CONFIG_PER_VMA_LOCK depends on CONFIG_MMU, the changes in nommu are
not needed.  Remove them.

Link: https://lkml.kernel.org/r/20230301190457.1498985-1-surenb@google.com
Fixes: bad94decd6a4 ("mm: write-lock VMAs before removing them from VMA tree")
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Reported-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Link: https://lore.kernel.org/all/Y%2F8CJQGNuMUTdLwP@localhost/
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>