GitLab

For the writer counter, it's pretty much the same as the reader counter,
and they are exclusive.  So move them to the new locked bitmap.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>