volume/local: Fix debug log typo
Active count is incremented, but message claimed the opposite.
Signed-off-by: Paweł Gronowski <pawel.gronowski@docker.com>
(cherry picked from commit 7f965d55c719b8777221c4dbf9a1eb93cfada8ab)
Signed-off-by: Paweł Gronowski <pawel.gronowski@docker.com>