Don't use self->mmap in pstore_extent__decompress()
Don't use self->mmap in pstore_extent__decompress()

We have two kinds of extents: mmap'd and buffered extents. Don't use self->mmap
in pstore_extent__decompress() because we're dealing with buffered extents
there.

Signed-off-by: Pekka Enberg <add4fcd06328a394f0ad91feda7ee057316dc5ed@cs.helsinki.fi>

penberg/pstore,penberg/pstore,penberg/pstore,penberg/pstore