mm/vma: update vma_assert_locked() to use lockdep

mm/vma: update vma_assert_locked() to use lockdep

We can use lockdep to avoid unnecessary work here, otherwise update the
code to logically evaluate all pertinent cases and share code with
vma_assert_write_locked().

Make it clear here that we treat the VMA being detached at this point as a
bug, this was only implicit before.

Additionally, abstract references to vma->vmlock_dep_map by introducing a
macro helper __vma_lockdep_map() which accesses this field if lockdep is
enabled.

Since lock_is_held() is specified as an extern function if lockdep is
disabled, we can simply have __vma_lockdep_map() defined as NULL in this
case, and then use IS_ENABLED(CONFIG_LOCKDEP) to avoid ugly ifdeffery.

[lorenzo.stoakes@oracle.com: add helper macro __vma_lockdep_map(), per Vlastimil]
Link: https://lkml.kernel.org/r/7c4b722e-604b-4b20-8e33-03d2f8d55407@lucifer.local
Link: https://lkml.kernel.org/r/538762f079cc4fa76ff8bf30a8a9525a09961451.1769198904.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Waiman Long <longman@redhat.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>