mm: call vfree instead of __vunmap from delayed_vfree_work

mm: call vfree instead of __vunmap from delayed_vfree_work

This adds an extra, never taken, in_interrupt() branch, but will allow to
cut down the maze of vfree helpers.

Link: https://lkml.kernel.org/r/20230121071051.1143058-6-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>